Inside the Kuoh Academy Occult Research Club room, things were calm. The heiress of the Gremory clan and the heiress of the Sitri clan were going over the information they had received from their older siblings about the Sword of Logos.
"So, according to what my brother told me, the Sword of Logos is a human organization that once took part in the three-way war between angels, devils, and fallen angels."
"They were also the ones who re-separated the Underworld from the human world when the Old Satan faction tried to merge both realms."
"That kind of feat… humans shouldn't be able to do that," Rias muttered.
"According to my sister, they used incredibly powerful holy blades. Ankokuken Kurayami, Kōgōken Saikou, and Mumeiken Kyomu," Sona explained.
"Holy blades…" Rias glanced toward her knight.
"But afterward, a family of blacksmiths created more holy blades to help protect the world. Now the Sword of Logos possesses eleven holy swords," Sona continued.
"Are they like Excalibur?" Tsubaki asked.
"No. Excalibur today is just a fragment of the original. Their blades are complete holy swords," Sona said.
"And those armored people we met were called Buster, Saber, and Calibur. Not their real names, just their titles. It seems my brother knows the one called Saber."
"So… they're not dangerous, Kaichou?" Akeno asked.
"Saber might not be. But the other two? Hard to say. Buster is known as the Swordsman of Land, and every Buster never hesitates to attack if it's to protect others."
"And the other one… Calibur."
"Calibur? Like one of King Arthur's swords?" Kiba asked.
"Yes. But this Calibur probably existed long before King Arthur," Sona answered.
"So King Arthur named his sword after that Calibur?" Koneko asked.
"Possibly."
"Whatever! I'll beat them if they mess with Kaichou!" Issei yelled.
Everyone just shook their heads.
Suddenly, a surge of powerful energy swept through the area.
"Kaichou!" both queens reacted.
"Yes!" Rias and Sona replied, and the group teleported to the source.
---
Ace dispelled the Thousand Demon Dagger and hung Kurayami at his waist. He carried Yami on his shoulder just as two magic circles appeared.
'Oh no… them again,' he thought.
Two girls stepped out: one with red hair, another with black hair and glasses.
"Yo. We meet again."
"What are you doing here?" Rias demanded.
"Just a small fight. Nothing serious."
"Have we met before?" Sona asked.
"You forgot? That abandoned house."
Sona's eyes narrowed as she spotted the sword at Ace's waist.
"Rias. That sword."
"Are you one of those armored people?" she asked.
"Bingo. But sorry, no prize."
"Kaichou! He kidnapped a cute girl!" Issei shouted.
"Issei, calm down."
"Why are you carrying her?" Rias asked.
"Think of it like… a lovers' quarrel. Also, you two really need to hunt stray devils more often. Kuoh is full of them. Are you even managing this territory?"
"You can't speak to Kaichou like that!" Issei and Saji summoned their Sacred Gears.
"Issei!"
"Saji!"
Ace blinked.
"Why are they pulling out Sacred Gears…?"
He sighed and looked at Rias and Sona.
"Please control your pawns. They'll die fast at this rate."
"Issei, come here."
"But—"
"Now."
"You too, Saji," Sona said.
"If that's all, I'll be heading out," Ace said, turning around.
As he walked, a thought bugged him.
'I have a theory about that weird feeling when I look into certain girls' eyes. It happened with Lala, then Yotsuya-san, then Yuki. System, is it connected to that manga… 100 Girlfriends?'
[Based on your memories, the phenomenon is similar, but different.]
'Oh? How?'
[In that manga, people fall in love instantly. What you experienced only triggers the dormant feeling.]
'That sounds the same.'
[Whatever.]
'…Did you say "whatever"?'
[That was your imagination.]
'You deleted the message!'
"Wait. What's your name?" Rias called.
'Alright. Let's test if any of them trigger that feeling.'
Ace turned back to face them.
"Current wielder of Ankokuken Kurayami, Akashi Ace."
He looked into Rias's eyes.
Nothing.
Then he turned to Sona.
Ka-ching!
'System… what do I do?'
[I suggest you pursue Sona, Host.]
'Why?'
[Because her feelings were already brewing beneath the surface. Even if you do nothing, they'll fade only after a long time. Besides, you're a future Galaxy King. She's the Sitri heiress. Marrying her would strengthen ties between Earth's supernatural side and the alien world. It's good political groundwork.]
'Couldn't we just cooperate normally?'
[Marriage bonds alliances better than cooperation. You could slowly introduce alien matters to the human world.]
'That's far in the future.'
[Planning ahead is important.]
Ace sighed.
"If that's all, I'll go."
"Wait," Sona called.
Ace paused. "Yeah?"
"Since our duties overlap a bit keeping this town safe, why don't we cooperate?"
[Accept it, Host.]
'Why are you so excited…?'
"Hm… fine. No harm in that. But this is cooperation with me, not the Sword of Logos."
He tossed two business cards, which Rias and Sona caught.
"Call if you want to discuss it. Ciao."
After he left, Rias quietly asked, "Sona, why did you suddenly propose a partnership? That's not like you."
"I just… thought it would be useful. He's not causing trouble, and having help is good."
"That's true, but we should've discussed it first."
"Sorry. I acted on impulse."
"It's fine. Let's head back."
---
While Ace was walking away.
"System, why didn't I feel much of that phenomenon's effect? I only felt a shock running through my whole body."
[That's because you were born that way]
"You make it sound like I don't understand what love means."
Back home, Ace set Yami on the couch before realizing something.
"…Why did I bring her home?!"
"Ace, who's this?" Lala asked.
"She's… an assassin."
"Then why bring her here?"
"I honestly don't know."
Craftbot floated toward the phone. Ace grabbed it by the head.
"Where do you think you're going?"
"I'm telling your mother you kidnapped a girl!"
"Don't you dare!" Ace yelled, throwing Craftbot away.
While they were arguing, Yami woke up and cut herself free.
Craftbot screamed, "Run, girl! I'll hold him off!"
"Stop making me sound like a criminal!" Ace kicked the robot into the backyard.
---
Timeskip
In class, Ace saw Masachika looking exhausted.
"How's your training with Ogami-sensei?"
"We're not doing real training yet. Just muscle building."
"Well, that's good. You need it. You lack muscle."
"That's cruel. Compared to Sarashina-senpai I'm weak, but don't compare me to Itadori! That guy's a gorilla!"
"Yeah, Ogami-sensei doesn't suit you. You're the strategist type. You'd do better with Daishinji-san."
"Who's that?"
"The Swordsman of Sound. He's also a technician. His sword style is more tactical."
Masachika thought about it. "Hmm…"
---
During break, they all gathered in the student council room. Miko joined because the council asked her, and Ace told her to come.
"H-hello… I'm Yotsuya Miko. Nice to meet you."
"Nice to meet you. I'm Kenzaki Touya, the current Student Council President. I heard you can see curses."
"Yes… before Ace gave me this bracelet."
"I called you here because of that."
"So… what can I help with?"
"A few days ago, a major incident happened at school involving a curse. Luckily no casualties. Because of that, I—"
"Kenzaki-senpai, stop trying to act mysterious. You invited her because you're curious. Birds of a feather flock together." Ace cut in.
"Akashi, don't interrupt people. It's rude," Sarashina said.
"Anyway, that's why we invited you, Yotsuya-san," Yuki added.
"Oh… I see."
"Great, now she's confused," Ace said.
"Alright, sit down, Yotsuya-san," Masha said.
"Excuse me," she murmured, taking a seat.
"So, Yotsuya-san, do you only know about curses?" Yuki asked.
"Yes… and honestly I'd rather not know more."
"Too late. You sat down, so you're in," Ace said.
They explained what they knew about the Sword of Logos and everything else.
Sarashina finally asked, "I've been wondering… Ogami-sensei talked about Wonder Ride Books, that they draw power from stories around the world. But he didn't explain enough. Could you tell us more?"
Masachika and Itadori nodded.
"Alright," Ace said. "Wonder Ride Books are actually fragments of the Book of Creation. They tore off during the war between angels, devils, and fallen angels—"
"Hold it! WHAT?!" Masachika and Itadori shouted.
"Oh… Ogami-sensei hasn't told you? Yeah, you've only trained a day. Makes sense."
"Angels and devils are real?!" Itadori asked.
"Yep. But relax. It's peaceful now."
"Please continue, Akashi," Kenzaki said.
"When a page of the Book of Creation is torn, a Wonder Ride Book is formed. Wonder Ride Books are divided into three types. First, the Book of God Beast, which contains mythical creatures, like Ogami-sensei's personal book that holds the power of the Black Tortoise. Second, the Book of Animals, which, as the name suggests, is about animals from the real world. Third, the Book of Stories, which contains heroic tales or fairy tales, like this one about the Three Little Pigs." Ace said while taking out the Three Little Pigs Wonder Ride Book.
"Cute," Masha said.
"But is it strong?" Itadori asked.
"It's versatile. Not strong. Like when I made that slide the other night. I can summon brick, wood, straw, and shape them."
"Oh right… I panicked so I didn't notice," Alya said.
"Any other questions?"
They shook their heads.
---
Meanwhile, Yuki noticed Lala reading something.
"Lala, what are you reading?"
"Hm? Oh, this novel. Swordsman in Wonder World."
"I know that one," Miko said.
"Me too," Yuki added.
"Why?" Itadori asked.
"It's popular for its worldbuilding," Miko explained.
"Yeah, volume three comes out next week," Yuki said.
"Do you like novel Suou-san?" Alya asked.
"Y-yeah, I read it sometimes."
"Which volume are you reading, Lala?" Miko asked.
"The third one."
"No way, volume 3 doesn't come out until next week."
"But look, this is volume three," Lala said.
"How is that possible?! Where did you get it, Lala?" Miko asked.
"Hm? From Kamiyama-san."
"Kamiyama-san?" Yuki and Miko said at the same time.
"You might know him as Kamito-sensei," Ace said.
"Ka-Kamito-sensei?! Isn't he the author?! Do you know him, Lala?" Miko asked.
"I don't really know him, but Ace seems to know him pretty well."
Yuki and Miko both turned their eyes toward Ace.
"Look, class is about to start. We should head back. Come on, Lala."
"Hey, don't run away!"
Ace pulled Lala back into the classroom.