Long ago, when the Earth was very young and fragile, there existed a peaceful realm where Guai, humans, and gods lived together in harmony. This place was full of lush lands, sacred temples, and divine presence, and it was considered a paradise.
But one day, a human trespassed into the Realm of Hell, unknowingly offending the powerful entities that guarded it. The gods of the four hells — guardians of punishment and balance — saw this as an affront.
炎獄 (En-goku) – Hell of Flames: Lava rivers, volcanoes, and fire demons. Punishment through fire and trial by burning.
氷獄 (Hyō-goku) – Hell of Ice: Frozen wastelands, glaciers, and frost beasts. Punishment through isolation and slow despair.
暗獄 (An-goku) – Hell of Shadows: Endless darkness, phantom assassins. Punishment through fear, illusions, and regret.
腐獄 (Fu-goku) – Hell of Decay: Swamps of rot, plagues, and undead horrors. Punishment through corruption and destruction.
In retaliation, the hell gods unleashed their wrath on the human realm, bringing destruction with a terrifying yet controlled precision. The chaos was immense, and only the most powerful god of death, Yanruo Wang, intervened.
Yanruo Wang defeated the hell gods and sealed them in different regions of the Earth:
South, East, West, and North, each containing the remnants of their hellish power.
The human who caused the offense was returned to Earth, but the Guai had already infiltrated the mortal world, living among humans in secret. Over time, humans learned to coexist with these beings, who carried the energy of Shijoku — the underworld power, Meiryoku.
The realm of Shijoku is no ordinary place. Those who are born within it, or carry its essence, are immortal by birth, for it is the destiny of Shijoku to grant life beyond the limits of time.
Shijoku exists between the human world and the world of the Guai, acting as a bridge of energy, life, and spiritual power. From this realm flows Meiryoku, the source of all power, connecting humans, monsters, and gods alike.
It is in Shijoku that the fate of all beings is intertwined — humans who trespass, Guai who wander, and overlords who rise — for whoever holds the essence of Shijoku holds the key to immortality, power, and the balance of world
Diazo Dori slowly opened his eyes, blinking against the morning light. His heart raced, still caught in the remnants of what he had seen.
"What… was that?" he whispered to himself. "A dream? Or… something else?"
He shook his head, trying to make sense of the fleeting images. Faces, places, powers — and then, unexpectedly, he saw his old friend again. The vision vanished, leaving only the faint echo of Shijoku in his mind.
"Maybe… it was just a dream," Diazo muttered, taking a deep breath. But deep down, he knew it was more.
"I… am Diazo Dori," he said, his voice firm. "A Kaijin. That is who I am… and who I have always been."
He stood tall, eyes blazing with resolve. "And now… I will be the teacher of the next generation of Kaijins. They will learn, they will fight, and they will protect the balance between humans and Guai… as I once swore to do."
Diazo Dori yawned as he walked down the sunlit footpath. "Another day… and another dream," he muttered. "Could the world really be like that? Is it possible?"
Birds chirped in the trees. Cars passed by. People hustled through the streets. "Maybe today I should do something… after all, it's my first day as the teacher of the Kaijins. I need to be polite with them," he thought. "Last year, things didn't go smoothly… but now? I can do it right."
As he walked, a commotion caught his attention: a thief was holding up an old woman's bag.
"Hey! Give me your money!" the thief demanded.
"Help!" the woman cried.
Diazo sighed, adjusting his posture. "Really, people. You shouldn't abuse your power like this," he said calmly.
The thief sneered. "Who are you?"
Diazo smiled faintly. "You may have heard of me. People call me Diazo Dori, but you… you can call me Mr. Polite. Doesn't it suit me?" He stepped closer, positioning himself between the thief and the woman.
"You think you can fool me?" the thief growled.
"I'm not here to fool anyone," Diazo replied evenly. "Now… put the gun down. Help is better than violence. Or… I will call the police."
The thief's eyes narrowed. "I'll shoot!"
Diazo raised a single hand. The bullet froze in midair, hovering inches from him.
"What… what is this?" the thief stammered, eyes wide.
"You really tried to shoot us?" Diazo said, unimpressed. "Disappointing. I don't like showing my power to ordinary people — rules are strict — but when someone needs help… I step in."
The thief panicked and tried again. The bullet froze again, this time sinking harmlessly into the ground. "No… it can't be! You're a monster!"
Diazo tilted his head. "Monster? Perhaps. But I'm polite too." He raised his hand again, and the gun gently flew from the thief's grip into his own palm. "You should never threaten my friends, or the innocent. Now…"
The thief trembled. "Please… don't hurt me!"
Diazo smirked. "Run if you like. But it won't be easy." With a calm flick of his wrist, the thief collapsed into a sleep-like state.
Diazo picked up the woman's bag and handed it back. "Here you go, Granny."
He turned, only to find… she had vanished.
Diazo blinked, scratching his head. "Wait… what? She ran? I wanted to help…"
He made a funny face, shrugging at the empty street. "Well… at least the Kaijins will learn from this. Politeness… and power."
Diazo Dori shrugged, his expression calm. "Guess… if I show my power, it might cause a scene," he muttered, placing the bag carefully on the police station counter.
After all his training as a Kaijin, he had grown incredibly strong. It showed in everything he did — careful, precise, and powerful. "We are Kaijins after all," he thought.
As he walked down the street, he muttered quietly, "I've lost so many things in life… a friend I wanted to see again. But… I guess I can't have them back."
A ball rolled across his path. A young girl picked it up and looked up at him.
"Is something wrong, mister?" she asked softly.
Diazo shook his head with a faint smile. "Nothing at all." He showed his face, and the girl immediately blushed.
"Wait… what? Why is he so… handsome?" she whispered.
Diazo tilted his head, his calm voice echoing gently. "Is something wrong?"
Another girl appeared, holding her notebook. "Hey Yori, everything fine?" she asked. Her eyes widened as she caught sight of Diazo.
"Wow… he's really handsome," she whispered.
Diazo smiled politely. "Wow… hey, girls."
The girls giggled, some leaning closer. "Can you… be with me?" one asked.
"It's okay to have feelings," Diazo said lightly, giving them a gentle smile.
"Hey, can we take a picture?" another asked.
Diazo chuckled softly. "We can talk later. I have somewhere to go now."
And with that, he started running down the street. "Run, run… bye!"
The girls called after him, hearts fluttering. "Wow… he's so handsome!"
Diazo smirked, a hand on his head as he ran. "Phew… that was close," he muttered.
Diazo Dori sighed, looking at the path ahead. "My life… I guess I can finally say it's taken a turn. I was feeling bad when I thought about my past… but now? I'm the teacher of the Kaijin Academy. Finally… we're here."
He approached the academy door and reached for the handle. Just as he was about to open it, a strange feeling prickled his senses.
"Something feels… fishy," Diazo muttered, eyes narrowing.
He paused, taking a cautious step back. Suddenly, a girl's voice came from behind:
"Gotcha!"
Diazo spun around in surprise. "What—?"
Before he could react further, a familiar face appeared. He caught her hand gently, recognition dawning.
"It's me… Sera. Your love," she said with a teasing smile.
Diazo blinked. "Oh… it's you? My bad, I didn't see you there."
Sera stepped closer, playful and confident. "My love, where have you been? Don't you want to cuddle?"
Diazo's eyes widened, and he made a funny face. "No thanks… why should I?"
Sera pouted, tilting her head. "We're couples, aren't we?"
"Wait… when did that happen?" Diazo asked, genuinely confused.
Sera giggled, nudging him gently. "Aww… don't you want to cuddle me, naughty man?"
Diazo crossed his arms, suspiciously. "Hmm… something's fishy here."
Sera's eyes sparkled, teasing. "Fishy? What's so fishy?"
Diazo tilted his head, a faint smirk forming. "You… suddenly calling me your love and wanting to cuddle? That's fishy."
Sera laughed, leaning closer. "So… you do care!"
Diazo just sighed, shaking his head with a funny face. "This is going to be a long day…"
Diazo Dori shook his head, brushing off the lingering thoughts from earlier. "Anyway… where are the new students? I want to meet them."
Sera smiled mischievously. "They're already in the room," she said, watching him with amusement.
Diazo strode confidently to the classroom door and swung it open with a flourish.
"Well helloooooo, students! It's me, your teacher… Diazo Dori!" he called.
Silence.
Diazo blinked, looking around. The classroom was… empty. No students. No chairs moved. Even the desks seemed untouched.
"Wait… what?" he muttered, his face frozen in a mix of confusion and frustration. His usual calm demeanor slipped into a comically blank stare.
Suddenly, a duster swung out of nowhere and hit him squarely on the head, leaving white dust in his blond hair.
"What?! Was that a trick?!" Diazo exclaimed.
Before he could react, a rope was thrown over him, tangling around his arms. "Hey! Who did that?!"
From the back of the room, a group of students giggled. "So… this clown is going to be our teacher? What a drag," one whispered.
Diazo narrowed his eyes, tugging at the rope. "Hey! I am not a clown, you three idiots!"
Another student, smirking, added, "Uh… I think you kind of are…"
Diazo sighed, pinching the bridge of his nose. "This is going to be a long day…"
One of the students leaned back, smirking. "So… you're done? What's your name again?"
"Daizo," he replied firmly.
The students exchanged glances, then one said with a grin, "We're going to knock you out!"
Diazo raised an eyebrow, calmly tugging at the rope still tangled around him. "You three are messy," he said, a small smirk forming. "And… you're in trouble."
The students paused, impressed but not intimidated.
"That's a very good trick," Diazo added, chuckling.
Just then, another student appeared from behind, voice teasing: "But won't that be enough? You know…"
Diazo, suddenly seated on the sofa with a calm, almost smug smile, looked down at them.
The students froze, shocked. "What… how?"
Diazo's smile widened. "It's Genso, you know…"
The rope around him vanished, and the Diazo who had been tangled disappeared, replaced by a fully free and relaxed version.
"But…" he continued, eyes narrowing slightly, "I still have to say… you three are troublemakers."
The students gulped, realizing that Diazo Dori was far more than he appeared — polite, funny… and extremely powerful.
Diazo crossed his arms, a calm smile on his face. "So… tell me. Are you ready?"
One of the students blinked, still wide-eyed from the earlier chaos. "Wait… how did he… do that?"
Another student whispered to the group, eyes shining with excitement. "That's Genso! It's his illusion skill… he can trick other Kaijins with it!"
The first student's jaw dropped. "No way… our teacher can do illusions?!"
Diazo, noticing their awe, chuckled softly. "Yes… Genso. But don't get used to it. I only use it when necessary. Now, focus — it's time to train."
The students gulped, realizing their polite, funny, but insanely powerful teacher was far more than they imagined.
Diazo Dori adjusted his posture, a calm smile on his face. "So… tell me. What are your names?"
The boy with striking blue hair spoke first, voice confident but respectful. "I'm Kaito Nakamura."
The boy with black hair followed, nodding. "I'm Hamura Yamato."
Finally, a quiet, serious-looking boy spoke. "And I'm Sei Sakurai."
Diazo's eyes sparkled with a friendly warmth. "Well, well… it's very nice to meet all three of you. I'm your teacher, Diazo Dori. Let's make sure your time here at the Kaijin Academy is… unforgettable."
The three students exchanged glances, a mix of excitement and nervousness bubbling up.
Daizo Dori leaned forward slightly, his calm smile encouraging. "So… tell me. Why did you guys want to join the Kaijins? That's the first thing I'd like to ask."
Kaito, the blue-haired boy, spoke confidently, eyes shining. "I want to save everyone, and I want to become the strongest Kaijin."
Daizo nodded, impressed. "Ah… that's a noble goal you have, Kaito."
He turned to Hamura, the black-haired boy. "And what about you?"
Hamura crossed his arms, expression serious. "I… don't want to discuss it."
Daizo raised an eyebrow, tilting his head with a faint chuckle. "Well… that's a bit rude, but alright. No problem with that. Everyone has their reasons."
Finally, he looked at Sei, her eyes determined. "And you?"
Sei's voice was steady. "I want to become someone who can do something for our city. I want to help as many people as possible… for the ones I care about."
Daizo's smile widened, a proud glint in his eyes. "Huh… you three are very good. Each of you has a strong heart and purpose. That's exactly what makes a Kaijin."
Daizo Dori chuckled, stretching slightly. "My name is Daizo Dori. As you know…"
Kaito, grinning, interrupted. "But you already said that, old man."
Daizo blinked, shocked. "Old man?! I'm only 21, my student! 😤"
He paused, smirking. "By the way… what kind of fun do you want to do today?"
Kaito, Hamura, and Sei exchanged confused glances. "What?" they asked in unison.
Daizo waved his hand. "Never mind. Forget I asked."
He clapped his hands. "Alright, let's explore the academy."
The three students nodded. "Alright!"
As they walked down the hall, Daizo glanced at them with a mischievous smile. "Hey… have any of you ever faced a Guai in your life?"
Kaito puffed up his chest. "Yeah… once I did."
Hamura smirked. "I killed two at once with my ability. It wasn't a big deal."
Sei shook her head. "I didn't fight… but I saw one."
Daizo laughed, shaking his head. "Oh? How about I show you a Guai? Or maybe… I'm a Guai who's hunting you right now."
Kaito froze. "What… are you saying?"
Daizo stepped closer, grinning. "I'm a Guai who will…"
The students stopped dead in their tracks, eyes wide in shock.
Daizo threw up his hands, laughing. "Relax! Just joking, funny face . Chill, guys. I was really just pranking you."
He opened a door at the end of the hall. "And… here we have our grandmaster, Mr. Saito."
An old man, slurping noodles, looked up and grumbled. "Hey, you bastards! Knock before you come in!"
Daizo bowed slightly. "Students… meet your principal."
Mr. Saito sighed, adjusting his glasses. "Anyway… you people should go. I have work to do. And… you should wear proper clothes for training."
Daizo nodded and reached for his gear. He wrapped himself in a long, flowing red cloth around his waist, the emblem of the Kaijins visible as it fluttered slightly.
The students hesitated, staring at their own outfits — long red cloths, matching Daizo's. "Wait… what's this?" Kaito asked, holding the fabric awkwardly.
Daizo smiled, adjusting his own cloth. "This," he said, gesturing grandly, "is the garb of the Kaijins. It's what we wear when we face Guai in battle."
Hamura frowned slightly. "So… we're actually going to fight them?"
Daizo nodded, eyes serious but calm. "Yes. Every Kaijin learns to protect, to fight, and to control their power. This cloth… it's a symbol. It shows who you are, and what you fight for."
Sei held her cloth tightly, determination in her eyes. "I… I want to be ready for anything."
Daizo grinned. "Good. That's the spirit. Now… let's see what you three can do."
Mr. Saito sighed, adjusting his glasses. "Anyway… you people should go. I have work to do. And… you should wear proper clothes for your kaijin work "
Daizo nodded and reached for his gear. He wrapped himself in a long, flowing red cloth around his waist, the emblem of the Kaijins visible as it fluttered slightly.
The students hesitated, staring at their own outfits — long red cloths, matching Daizo's. "Wait… what's this?" Kaito asked, holding the fabric awkwardly.
Daizo smiled, adjusting his own cloth. "This," he said, gesturing grandly, "is the garb of the Kaijins. It's what we wear when we face Guai in battle."
Hamura frowned slightly. "So… we're actually going to fight them?"
Daizo nodded, eyes serious but calm. "Yes. Every Kaijin learns to protect, to fight, and to control their power. This cloth… it's a symbol. It shows who you are, and what you fight for."
Sei held her cloth tightly, determination in her eyes. "I… I want to be ready for anything."
Daizo grinned. "Good. That's the spirit. Now… let's see what you three can do."
Daizo Dori leaned back, letting out a small sigh. "Well… for now, we don't have any urgent work. So… let's just sit back and do nothing for a bit."
The students blinked at him. "Wait… do nothing?" Sei asked, confused.
Daizo waved a hand, smiling. "Don't worry. I'll come by later. Right now, you guys enjoy yourselves. I have to go handle something I need to take care of."
He stood, adjusting his red Kaijin cloth, and began walking toward the exit.
Kaito called after him, frustrated, "Hey! Wait… damn it!"
Hamura crossed his arms, shaking his head. "I didn't expect this from him at all…"
Sei just giggled softly, watching him leave. "He's… really something else," she whispered.
Daizo's laughter echoed faintly from down the hall. "Relax, students! A little patience builds character."
Daizo Dori stretched, watching the students fidget with excitement. "Alright… we need to train properly. Go on a mission by yourselves, see what you can handle."
Hamura raised an eyebrow. "Hmm… how?"
Kaito looked curious. "Yeah, how are we supposed to do that?"
Hamura smirked. "I found a document when I was checking the place. It lists some low-level Guai nearby. How about we take that as our training mission?"
Kaito's eyes lit up. "Yeah! Sounds good!"
Sei nodded thoughtfully. "Good option… since we don't have any orders right now, it's better than just sitting around."
Kaito grinned. "Who cares? Let's take the mission!"
Hamura crossed his arms, voice calm. "It's low-rank Guai anyway… shouldn't be too hard."
Kaito blinked, impressed. "Low-rank, huh? Well… alright then. Let's settle this mission.
Kaito smirked at Hamura and Sei. "Heh… the old man, Saito, doesn't even know about this, right?"
From somewhere in the office, a loud sneeze echoed.
"Ah-choo! Did someone miss me?" came a gruff but playful voice.
the principal's office, Mr. Saito smirked, slurping the last of his noodles. "Never mind… I guess some girls will be missing me anyway," he muttered with a wink.
Kaito groaned, shaking his head. "Let's just go…"
The scene shifted.
Daizo Dori stood alone in a wide-open field, surrounded by soft petals drifting in the breeze. His long Kaijin cloth flowed like fire, striking against the pale landscape. The students' red uniforms mirrored his cloth, but here, Daizo's presence was commanding — his blond hair glinting under the sun, eyes sharp with focus.
Every movement was deliberate. The wind caught his cloth, making it dance around him, and the petals swirled like a river of red. The aura of Shijoku energy — Meiryoku — seemed to hum faintly in the air, visible only to those sensitive to spiritual energy.
He exhaled slowly, taking in the moment. "Time to see what I'm truly capable of…"
Daizo walked slowly through the quiet field, the petals of red Kaijin cloth trailing behind him in the wind. He came to a small grave, partially overgrown, and knelt beside it.
In his hand, he held a single rose 🌹, placing it gently atop the stone. His voice was low, trembling slightly with restraint.
"I'm sorry, Haruki… Haruno," he whispered. "I couldn't save you… not like I promised."
He closed his eyes, taking a deep breath as the wind rustled his blond hair. "Sen Tenma… I couldn't bring him back either. He… he chose the dark. I tried to pull him with me, but he didn't. He's gone."
A faint, sad smile touched his lips. "I try to find solace… when I see you, when I remember the friendship we once had — you, me, Sen… but we're no longer the same. I miss those days."
The wind picked up, tearing through his red cloth and tousling his hair, carrying the petals like memories across the field. Daizo's gaze lifted to the horizon, eyes shimmering with quiet pain, determination, and longing.
"Even so… I will keep walking. I will protect what remains, and I will honor the promises I could keep."
He placed the rose firmly on the grave, bowing his head one last time, the weight of the past heavy but resolved.
A few hours later, Daizo noticed a girl placing flowers at a grave nearby. Her movements were careful, delicate… but there was something about her presence that tugged at his attention.
After some time, she started walking away. Daizo followed silently, keeping his distance.
The girl felt a strange sensation, like someone was watching her. She glanced behind, and her eyes widened. "Wha… who's there? Is someone chasing me?"
She quickened her pace, entering a small alley. Suddenly, a group of rough men blocked her path.
"Hey, lady! Lost here? Need some help?" one sneered.
"Go away!" she snapped, throwing her bag at one man's face. He stumbled back, eyes wide in shock.
She turned, ready to run again, and froze — Daizo was standing there, calm, his usual mischievous smile playing on his lips.
"Who… who are you?" she stammered.
From behind, the men's voices grew rougher. "They're Guai!" one shouted.
"What?" she gasped.
Daizo's eyes glinted. "I'm here… finance," he said smoothly, stepping closer.
"Am I… right, honey?" he teased lightly, assessing the danger.
The thugs froze, realizing they were outmatched.
Daizo grabbed her hand. "It's not safe here. Come with me." With incredible agility, he leapt onto the rooftops, pulling her along.
The girl barely kept up, her heart racing. "What… what's happening?" she shouted.
"They're Guai," Daizo said, holding her firmly by the shoulder. "And they're waiting for fresh meat."
As they jumped from rooftop to rooftop, Daizo's red Kaijin cloth fluttered wildly in the wind, and his blond hair caught the sunlight, making him look like a guardian of fate itself.
The girl's eyes widened, a mix of fear and awe. "I… I can't believe this…"
Daizo smirked lightly. "Believe it. And try not to scream too loud… we have work to do."
Daizo glanced at the girl, his eyes calm but piercing. "Don't worry… I'm here to save you. Since we can hunt Guai, leave the rest to me."
The girl shivered, stepping back, unsure of what to do.
Suddenly, the Guai shifted — their bodies twisting and merging into monstrous forms. They lunged at them, roaring with unnatural fury. The girl closed her eyes, bracing for the worst.
Daizo didn't flinch. In a swift motion, he raised a hand, and one of the Guai erased instantly, smoke curling where it once stood. Another Guai burst into flames mid-charge.
"You know," Daizo said, his voice calm but teasing, "you shouldn't play with fire, Guai. Seriously."
The remaining Guai combined, their bodies forming a massive, towering monster. Its roar shook the air, echoing across the rooftops.
Daizo's gaze hardened. "Since you've already done something very wrong here… I guess it's my turn to fix it."
He lifted his hand, his Meiryoku energy flaring visibly around him. "Here… I end your life."
The Guai exploded in a brilliant burst of light, their bodies obliterated by Daizo's overwhelming power. Smoke and wind swept across the rooftops as he lowered his hand, calm and unshaken.
She looked at the shattered ground, still trembling.
"W-What was that… really?"
Daizo turned slightly, a faint smile on his face.
"It was nothing. Don't overthink it."
She stared at him.
Nothing? That wasn't nothing.
Suddenly, he stepped closer and gently held her wrist.
"Hey, lady. Be ready."
"W-Ready? For wha—"
Before she could finish, the air burst beneath them.
In an instant—
They shot high into the sky.
Wind roared past her ears. The city below became tiny lights.
"D-Daizo?! We're too high!!"
He stood midair calmly, Meiryoku glowing faintly around them.
"Relax," he said softly. "I won't let you fall."
He adjusted his stance, then slowly descended, landing smoothly on a rooftop.
Silence.
She was still holding onto him.
He looked down at her.
"You're safe."
🎬 Clean Version – With "Human"
She looked at him seriously.
"…Are you human?
Or are you like the rest of them?"
Daizo stayed silent for a moment.
The wind moved his hair slightly.
"I am human."
She relaxed a little—
"But not just human."
Her breath caught.
He stepped closer, voice calm.
"I'm a Kaijin."
The word felt unfamiliar… heavy.
She stared at him.
"…What's your name?"
He met her eyes.
"Daizo Dori."
A small pause.
"Also known as… the most polite man."
She blinked.
"…Polite?"
He smiled faintly.
Yes
Daizo turned slightly.
"I guess… I'm done here."
She quickly stepped forward.
"Wait!"
He paused.
"…Will I see you again?"
A small silence.
Then he smiled.
"Sure."
He leaned slightly closer.
"But only if you don't scream next time."
She laughed softly.
"I didn't scream this time."
He nodded.
"You'll be one of those humans."
She tilted her head. "What do you mean?"
"There are a few," he said calmly.
"Humans who don't panic when I save them."
He looked at her properly now.
"I can count them on one hand."
A pause.
"I think you're one of them."
Her heart skipped.
"You think so?"
He gave a small shrug.
"I believe rare things are worth remembering."
Before she could reply—
📱 Phone rings.
Daizo makes a slightly annoyed face.
"…Wait. What?"
He checks the screen.
"…It's late."
He suddenly looks serious.
"I gotta go."
"Wait—!"
But he was already running.
Not normal running.
Fast.
In seconds he disappeared between buildings.
🎬 Scene Cut – Phone Call Chaos
📞 On the phone:
"DAIZO!"
It was Mr. Saito.
(You can later define him as principal, supervisor, or Kaijin handler.)
"Where is my document?! And why are you not at the trip location?"
Daizo froze mid-run.
"…Trip?"
"Are you with the students?!"
Silence.
"…I thought they were with you."
"WHAT are you saying?! They are NOT here!"
Daizo stopped completely.
His expression dropped.
"…Oh."
A long pause.
"…Nah, man."