To complete Kaede's mission, Rin had to develop both Ichika's interest in being cucked and the sisters' interest in doing the cucking.
Back at the house, Rin had pretended not to realize they weren't Ichika while kissing and fondling them; that was the first step in fostering their "infidelity" streak. The quintuplets valued their bond above all else. Fair competition was one thing, but right now, Rin's official status was "Ichika's Boyfriend." Rin didn't necessarily need to turn them into home-wrecking fetishests, but he at least had to make them comfortable with the idea of taking something that belonged to Ichika.
"I..."
Miku's brain had short-circuited. Only one thought looped through her mind: I was kissed. I was kissed by Ichika's boyfriend. There was no room for excuses. She hadn't been wearing a disguise; she had been kissed as Miku Nakano.
"I... I have to go."
Looking dazed, Miku walked toward the door. Rin didn't stop her, nor did he pull the classic "don't tell Ichika" card. He bet that while Miku would be conflicted, her inherent honesty would drive her to tell Ichika—even if she planned to "steal" him, she'd feel the need to declare it.
Miku sat at her desk back in the living room and lowered her head. The words in her textbook blurred. The phantom sensation of his lips lingered.
"It's getting late. Don't head back too late," Ichika said.
"Eh?" Miku snapped out of it. It was already 9:00 PM. She had spent the last hour in a trance, barely remembering the world around her.
"What are you doing sitting there looking stupid?" Nino slapped Miku's shoulder. Miku flinched and avoided Ichika's eyes.
After packing her things, Miku headed home with her sisters. The moment they arrived, she locked herself in her room. Unlike Ichika's messy studio, Miku's room was filled with traditional Japanese decor—scrolls and folding screens that looked like they belonged in a period drama.
She flopped onto her bed, her pink hair splaying across the pillow. He recognized me even in disguise. He knew my secret hobbies that not even my sisters know. He saw through my act of mimicking the others... Her heart, usually guarded, had been breached. Her feelings for Rin had transcended "friendship." But he was Ichika's.
I'm so envious. If only I had met him first.
But it was too late. He was Ichika's lover. If the previous incidents were "accidents," she could have kept them secret to protect the relationship. But this time, he had kissed her intentionally. This was cheating.
Tomorrow. I'll tell Ichika tomorrow at school.
The next day, during lunch break, Miku pulled Ichika away to a secluded spot under the trees by the school track. The hot wind rustled the leaves, mixing with the hum of cicadas. Miku's palms were sweating, and the heat trapped inside her black tights made her legs feel damp and heavy.
"What's up? Why the secret meeting?" Ichika asked patiently.
"Last night... he said I was... cute." Miku hesitated. She didn't mention the "full house under the bed" incident yet, just last night.
"Well, you are cute, Miku!"
"He... he... he also kissed me."
"Huh!?" Ichika's voice jumped an octave. "What happened?"
Miku recounted the scene in the bedroom. Ichika listened, realizing that Rin had made his move and Miku was likely falling for him, but was confessing out of a sense of sisterly duty. This put Ichika in a tough spot. She wasn't his real girlfriend, but she knew he had plenty of others.
Seeing Ichika's troubled expression, Miku bit her lip. "I'm not trying to steal him. I just wanted to tell you... he's a player."
"Wait, give me a second."
Miku watched as Ichika pulled out her phone and started typing furiously. She assumed Ichika was confronting Rin. In reality, Ichika was messaging Kaede.
Ichika: [Your boyfriend kissed my sister last night!] Kaede: [So? It's just a kiss.] Kaede: [You had a deep kiss with him, too. Tongues and everything.] Ichika: [My point is my sister likes him now! You're going to get cucked!] Kaede: [Your sister wants to cuck me? Please. Even if all five of you tried at once, it wouldn't matter.] Ichika: [...]
Ichika didn't know whether to be offended or impressed by Kaede's confidence.
Kaede: [I've 'lent' him to you. He's your boyfriend now. You decide what to do.] Ichika: [Don't come crying to me when he's gone!]
Ichika put her phone away. Kaede's provocations had worked. Ichika had been feeling the line between "acting" and "reality" blur for days. To develop the "cuckold" fetish, Ichika first had to believe she truly "possessed" Rin, so that the "loss" to her sister would feel significant.
Ichika looked at Miku. "Do you like him?"
"I... I..."
"Never mind, I know the answer." Ichika saw it in her eyes. Miku loved him, but she was choosing her sisters over her heart. In Ichika's mind, a plan formed. If the sisters could all love the same man, they would never have to drift apart after graduation. They could be like Kaede and Rin's circle.
But she had to frame it right. She had to lower Miku's guilt.
Ichika leaned in and whispered into Miku's ear: "Actually... I have a 'cuckold' fetish. I enjoy being cheated on."