Dishes washed, showers finished.
The four Nakano sisters once again subjected Rin to the "identification test." Since Rin had moved into the Nakano apartment, they had conducted this test four times.
Although tomorrow was technically the original deadline, Nino had issued a strict command: Rin had to pass today. If he failed again... Hmph!
Today, they returned to their original setup: wearing sleeveless plain white sun dresses and waist-length pink wigs, walking out of the room one by one. Previously, Rin had intentionally guessed wrong to tease the prickly Nino and to find excuses for "Deepening Our Understanding"—and every single time, he had "mistaken" Nino for someone else.
But today, he had teased her enough. If he kept it up, Nino would truly explode.
The first to head downstairs was Miku, followed by Itsuki and Yotsuba. Previously, they would cheat for him, but after realizing Rin was failing on purpose, they had stopped helping. They simply stood before him with quiet smiles, saying nothing.
During the past few days of "Deepening Our Understanding," Rin had mostly studied the parts of them covered by clothing—the way their nipples reacted to stimulation, or the subtle structural differences in the most sensitive areas between their legs when aroused.
Rin had indeed studied them meticulously, but that knowledge was useless while they were fully clothed. However, Rin already had extensive experience distinguishing between twins. After living with them for several days, he could tell them apart by their subconscious habits, posture, or subtle facial expressions.
Finally, Nino walked down to the living room.
Like the others, she remained silent with a smile on her face. However, when she stood before Rin, she intentionally let the strap of her dress slide off her shoulder, revealing the "Token of Commitment" hanging from her breast.
She cupped her left breast, letting the jewelry sway provocatively, glared at Rin with a "don't you dare" look, and shook her fist before pulling her dress back up and heading upstairs.
A moment later, the four of them removed their wigs and came back down together.
"Miku, Itsuki, Yotsuba, and Nino... correct?"
"Bingo!" Yotsuba lunged forward and hugged Rin. "You got them all right!"
"Congratulations."
"Mmm... congrats."
Itsuki and Miku clapped lightly in celebration, while Nino maintained her tsundere facade.
"Hmph... you're pretty pathetic. It took you this long just to tell us apart," Nino huffed, crossing her arms over her chest. "But since you finally did it, I guess you're barely passing."
Itsuki and Yotsuba bit their lips to keep from laughing. Even Miku's lips curled upward. Nino was the one who wanted him to pass the most; every time Rin had "failed" before, she looked like she wanted to murder him. Now that he succeeded, she acted as if it were a trivial matter.
She really is a textbook tsundere.
"Since you passed, there's no need for 'Deepening Our Understanding' tonight, right? Hmph... that 'understanding' was just an excuse to mess with us! I'm going to my room!"
Seeing her sisters' teasing gazes, Nino's face flushed hot, and she tried to flee, but Itsuki called out to her.
"Wait a second."
"What? If you guys want to keep 'understanding' him, go ahead and do it yourselves!"
"It's not that," Itsuki sighed helplessly. "Since he can finally recognize us, the question is... when do we tell Ichika?"
For the past few days, Ichika had been kept in the dark, including the fact that Rin was living in her room. This was because their mother and grandfather always said that "if there is love, you can tell them apart." That was why Nino had insisted on the test.
Miku had said Ichika wouldn't mind, but they wanted to wait until Rin officially passed before coming clean. However, in their hearts, they knew he was Ichika's boyfriend. As her sisters, the four of them had done many lewd and "shameful" things with Rin.
Nino, Yotsuba, and Itsuki had no idea how to face Ichika, so...
The three turned their gaze toward Miku. After all, Miku was the first among them to fall for Rin, and she claimed Ichika knew and supported her.
"I'll go talk to Ichika. She definitely won't mind," Miku promised.
"I hope so..." Nino was still worried. "Miku, you... you didn't lie to us about Ichika agreeing just to drag us all into this, right?"
Nino feared that Ichika, despite being the oldest, wouldn't be generous enough to share her lover with four sisters. If Rin weren't Ichika's boyfriend, Nino would have claimed him first and fought anyone who tried to share. Judging others by her own standards, she feared Ichika was being blindsided by a "fait accompli" orchestrated by Miku.
"Don't worry," Rin interrupted. "Ichika does know about Miku. Otherwise, do you really think I'd be staying here?"
"Hmph... who knows? Men are all fickle bastards!" Nino rolled her eyes at Rin before looking back at Miku. "Fine, you talk to her. We've only seen her at school lately. Ask her when she's free."
"Mmm..." Miku nodded. However, she wasn't thinking about how to tell Ichika; she was thinking about how to give Ichika a surprise!
She didn't just want Ichika to find out she was being "cucked"—she wanted Ichika to see she was being cucked by all four sisters simultaneously!
Miku had been reading quite a few doujinshi lately.
Following the logic of those stories... should they hide Ichika in the closet to watch?
Should they record it and send her the video?
Or should they throw a full-blown "party" in the apartment right after Nanami's tutoring ends, so Ichika walks in on it the moment she opens the door?
Miku liked all those ideas. But since they were quintuplets, the ultimate "Netori" element was the lover mixing them up! No matter the format, they had to all dress as Ichika on that day!
"Ichika shouldn't be out of her filming yet. I'll ask her tonight when she's free..." Miku's words caused the sisters to look at Rin.
"What? I can recognize all of you now. No more 'Deepening Our Understanding' needed," Rin said, putting on a solemn act of loyalty to Ichika. "I am Ichika's boyfriend. Everything before was just to get to know you better. Now that I do, I won't touch you again until you tell her the truth!"
"Hmph..." Nino sneered. "Passing that was just the beginner level."
"Yotsuba! Itsuki! Pin him to the sofa! Miku, go get your headphones and put them on him!"
Nino barked orders with a triumphant chin-lift. She ran to her room and grabbed several pairs of her frequently worn white thigh-high silk stockings.
Yotsuba and Itsuki sat on Rin's thighs, one on each side, pinning him to the sofa. When Miku returned, she clamped the headphones over his ears. Nino then used the silk stockings to bind Rin's hands behind his back and used another pair as a blindfold.
The stockings were freshly laundered, so Rin only smelled a faint, clean scent.
"Hey, hey... what are you doing?"
"Hmph... this is the Advanced Test. You have to distinguish us while blindfolded."
"But—"
Before Rin could finish, Miku pressed play on a loud track at Nino's signal. Nino knelt before Rin with a wicked smile and reached for his trouser button.
"So smelly... Chu~"
Despite her words, Nino kissed his tip softly as soon as she pulled his pants down to his ankles. Feeling the warmth of her lips, Rin's body reacted instantly, hardening with excitement.
Nino signaled her sisters, and the other three knelt down as well.
Miku and Yotsuba took the front-left and front-right positions, while Nino and Itsuki stayed on the sides of his thighs. Then, the four of them leaned in simultaneously, offering their lips and tongues.
"Hiss..." Rin sucked in a breath.
With four girls crowded together, space was tight. Even with their cheeks pressed against each other, they could only manage soft kisses and light licks with the tips of their tongues.
However, the sensation of four warm, flexible tongues flickering over him while he was blindfolded made a vivid image flash in Rin's mind. The mental stimulation and the sheer sense of conquest—being serviced by four identical sisters at once—was more intense than anything he had felt before.
Just then, Nino whispered the new rule into his ear, her voice barely audible over the headphones.
"You only get to 'come' once you correctly guess whose mouth you're in~"