"You two..."
The moment Rin and Itsuki returned home, Nino poked her head out from the kitchen, her eyes narrowing with intense suspicion as she scanned them. Itsuki, guilty as charged, pretended not to see her sister and bolted straight for the second floor to hide in her room.
Itsuki's guilt didn't stem from meeting Mudou; it was because she had actually called Rin "Daddy" earlier.
Even if it was a joke, Nino was her sister. Calling him "Daddy" was effectively making him Nino's father too.
Seeing Itsuki's flustered state, Nino knew she was in trouble.
Clutching a kitchen knife, Nino wordlessly dragged Rin into the kitchen and pointed the blade at him with a deadpan expression.
"Talk. What happened?"
Nino wasn't stupid. She could tell by the look on Itsuki's face that their relationship had shifted.
Today was a break from tutoring—not because Rin thought the girls needed it, but because he thought Nanami deserved a rest. Nino was prepping dinner; Yotsuba, having just returned from track club, was in the shower; and Miku was cooped up in her room.
"Well... nothing much," Rin said carefully, pinching the back of the knife and gently taking it from Nino's hand. "I just helped her firm up her resolve to chase her dreams."
"Huh?" Nino knit her brows, clearly unconvinced.
"Itsuki was worried her grades were too low to become a teacher. She was lost... it was a small thing she didn't feel comfortable telling you guys."
"I see... hmph." Nino clicked her tongue. "Honestly, if you want to be a teacher, study. If not, give up. What's there to be lost about?"
Rin didn't mention Mudou. This was family business; whether Itsuki shared it or not was up to her. He had no intention of interfering further.
Nino didn't press him. She was far more concerned about the "test." Since she had already been "conquered" by him, the test was technically meaningless. She just wanted him to pass it so things could become official.
"Hey, after dinner, we're doing the test!"
"Wait, didn't you say I had a week? It's only the third day. No way, let's do it next week," Rin said, shaking his head.
He had used "Deepening Our Understanding" as an excuse to get intimate with Miku and Yotsuba, but he hadn't had his way with Itsuki yet. Passing too early would end the game. Besides, this excuse allowed him to make them do all sorts of shameful things.
And then there was Nino. Rin knew she wanted him to pass, but his perverse side wanted to hear her beg for it.
"Ugh... how about a 'mock test'? We'll do one every day. Even if you fail, you can keep trying until next week. You just need to pass once to win the whole thing."
"Well... fine. If you insist, I guess I'll participate."
"Enough with the attitude!" Nino glared at him. He was clearly getting exactly what he wanted and still acting like he was doing her a favor. If he passed, he'd officially be the "lover" of all five sisters, yet he kept dragging it out.
He was a sadist. Rin could tell Nino was throwing the game, but the more she tried to help him win, the more desperate she became—and a desperate tsundere was a cute tsundere.
"I propose we test him every day until next week. One pass is all it takes."
Yotsuba: "Agreed!" Itsuki: "Agreed." Miku: "Agreed..."
At the dinner table, Nino's proposal was met with unanimous support. After the dishes were cleared, the four sisters huddled in Miku's room.
During the last test, Rin had insisted they come out one by one to make it harder. Nino wanted to make it easy, but her pride wouldn't let her make it too obvious.
"Miku, your room... your taste is so weird. Whatever." Nino shook off the decor; she had a mission. "Last time we removed all our distinguishing features. This time, let's all dress as Ichika! To make it harder, we'll even wear the exact same outfit!"
"And remember, go out one at a time. Do not tell him the answer!"
"No problem. We definitely won't tell him," Itsuki said, stifling a giggle.
They all wanted him to pass. Nino was just too stubborn to say it directly. Her "warning" not to tell him was actually a coded instruction to find a way to cheat for him. By going out one by one, it was easier to feed him the answers.
"Rock, paper, scissors!"
They quickly decided the order. Rin sat in the living room, waiting. Soon, the door opened and 'Ichika' stepped out.
"Shh~~ How do I look? Just like Ichika, right?"
'Ichika' put a finger to her lips and did a light twirl. She didn't even try to disguise her voice. It was obviously Yotsuba.
"I didn't know you could pull off Ichika so well, Yotsuba."
"Hehe~" Yotsuba grinned mischievously. "I'm first. Next is Miku, then Nino, and Itsuki is last. Got it?"
"Got it. Don't worry."
Next was Miku. She also whispered her identity immediately. "Yotsuba was first. I'm second. Then Nino and Itsuki."
"Perfect."
Then came Nino.
"Guess who I am, Big Brother~?"
While the others had leaked the answers, Nino tried to stay in character as Ichika. She wanted to help, but she couldn't bring herself to cheat openly. She assumed one of the other "traitors" had already told him.
"Hmm... this is tough. You look exactly like her." Rin furrowed his brow, acting as if he were in deep thought.
Nino's lip twitched. She had left several obvious "tells" in her acting. If he couldn't see through this, he deserved to be dumped by the real Ichika!
After her performance, Nino went back upstairs. She wanted to ask if the others had told him, but her pride stopped her. She handed the wig and outfit to Itsuki.
Finally, it was Itsuki's turn. She didn't state her name. Instead, she leaned into Rin's ear and whispered, "Daddy~"
The flirtatious tone made Rin's heart skip a beat. After Itsuki changed back into her normal clothes, all four gathered in the living room.
"Well? Have you decided?" Nino asked, crossing her arms under her heavy breasts. Surely someone told him?
"Sigh... this was much harder than last time. I couldn't use the process of elimination since I saw you one by one."
"Hmph... that's what you get for being so high and mighty! You brought this difficulty on yourself. What's your answer?"
"Ahem..." Rin cleared his throat. "First was Yotsuba. Second was Miku."
"Wooo!" Yotsuba cheered while Miku nodded with a smile. Nino exhaled in relief. Good, someone cheated for him. He's just acting.
"Third... Itsuki! And fourth was you, Nino!"
"What!? I was third, you idiot!"
Hearing Itsuki's name in the third slot, Nino bared her teeth, wanting to punch him. The other three looked at Rin in confusion. Why did he get it wrong on purpose?
"Eh? You were third, Nino? I thought it was Itsuki... Man, I guess I don't know you and Itsuki well enough. I could tell Miku and Yotsuba apart easily."
"You..." Nino's face twitched.
She realized exactly what he was doing. He was failing on purpose so he could demand more "Deepening Our Understanding" sessions.
"S-since that's the case, I guess we have to deepen our understanding," Itsuki said, adjusting her glasses and suppressing a laugh. "We can't have you mixing us up later."
"Well... yeah. It would be bad if I mixed you guys up later. Very bad," Nino muttered, her eyes darting around as she pretended to be reluctantly convinced. Her sisters struggled not to laugh at her blatant tsundere act.
"What's with those faces? As Ichika's boyfriend, he has to be able to tell us apart!"
"Hehe, since Nino says so, let's begin~" Yotsuba ran behind Nino and pushed her toward Rin. "First, let's test the softness of our lips and tongues~"
"Wait—mph!!!"
Before Nino could protest, Rin blocked her mouth. With Rin in front and Yotsuba behind, Nino was trapped. She could only let Rin taste her tender lips. Initially, she kept her mouth shut in resistance, but just like that day at Rin's house, she collapsed quickly. Her mouth was tough, but her lips were soft.
Yotsuba wasn't idle either. Her hands expertly began unzipping the tracksuit Nino had borrowed from Miku. Itsuki watched, wide-eyed, covering her mouth. Eavesdropping from a hallway was one thing; watching it live was another. And today, she wasn't just an observer; she was a lead actress.
Rin eventually let go, a silver thread of saliva stretching between their lips. Nino's dazed, lustful eyes were on full display for her sisters.
"Mph!!! Pervert!!!" Nino finally snapped out of it and shoved him away. Flushed and furious, she wiped her lips with the back of her hand.
"Hmm. Your mouth is stubborn, Nino, but your lips are soft. Next is Itsuki."
"O-okay!!!"
Though it wasn't her first kiss with Rin, Itsuki was so tense her whole body was stiff. Unlike Nino's performative pride, Itsuki was genuinely nervous. But under Rin's gentle touch, she melted, opening her lips to welcome his tongue.
"Hmm... Nino resisted at first then started sucking my tongue. Itsuki was a bit lost at first, but she became very cooperative once she got used to it."
"Who—who sucked your tongue!? You pervert!" Nino screamed, while Miku and Yotsuba stifled their laughter.
"But to really tell the four of you apart, I need to kiss everyone again."
Rin tasted each of them in turn, not missing a single pair of tender lips. "The lips are too similar. We need to go deeper."
"Understood, Sir~" Yotsuba stood straight and gave a mock salute before gleefully helping Nino out of her clothes.
"Wait... wait, don't take my clothes off..." Even the proud Nino could only manage a shy whimper as her outfit was removed.
Miku and Itsuki were much quieter. Miku undressed herself, while Itsuki, seeing the situation, began nervously unbuttoning her uniform.
"No, the bra has to come off too," Miku said, snapping Itsuki's bra strap loose.
"Kyaa!!!" Itsuki instinctively covered her chest. "I can do it myself!!!!"
Amidst the chaos, all four stripped naked. Seeing Nino trying to hide her breasts, Yotsuba grabbed her wrists from behind and pulled her arms back, exposing her most delicate parts to Rin's gaze.
"Hehe, you have to put your hands behind your back. He needs to see the differences clearly so he doesn't mix us up when we're naked!"
"Yotsuba, when did you become his accomplice!?" Nino glared at her sister.
"Ahaha..." Yotsuba laughed it off. Between her athletic nature and her burgeoning desires, she was becoming addicted to the feeling. Two days ago, Rin's fingers had sent her to a peak she'd never known. If his fingers felt that good, she couldn't wait for the real thing.
Four identical quintuplets sat in a row on the sofa. A sea of soft skin, firm breasts, and plump thighs filled Rin's vision. Despite his vast experience with "parties," this was a spectacular first.
However... it seemed there was a traitor among them.
Rin walked between Itsuki and Nino, cupping their breasts and weighing them. Then he compared Itsuki to Yotsuba and Miku.
"Itsuki... your breasts seem slightly larger than the others. I wouldn't have noticed without touching them."
"""Eh!?""" "Huh?"
Before Itsuki could react, her three sisters surrounded her, hands flying everywhere.
"Stop—ow! Nino, that hurts! Why are you squeezing so hard? Squeeze your own! Ahhh!!! Miku, don't poke me there, I'm ticklish! And Yotsuba! Where are you touching? Don't go any lower!!!"
Itsuki was treated like a life-sized doll, unable to fight back against the combined strength of her sisters. The "traitor" had to be punished!
After a while, Itsuki lay sprawled on the sofa, looking "broken," while her sisters reached their verdict.
Nino: "Itsuki's breasts are definitely bigger. And her waist... hmph, that's what you get for eating so much. Even with your sit-ups, you have a little extra meat there."
Yotsuba: "Miku, you need to exercise. Your waist is a bit..."
Miku: "I-I don't think so?"
They had always assumed they were identical, never having compared themselves so minutely while naked. Up close, the differences were clear. Yotsuba was the most toned, with a firmer butt and tighter skin. Miku was "physical trash," soft and squishy. Itsuki was the heaviest, her waist slightly wider than the rest.
As they discussed their bodies, Rin joined in with his "expert" evaluations.
"Hehe, so who has the best body among the four of us?" Yotsuba asked. Even among sisters, there was a competitive spirit.
"Hmm... Nino's body is the most balanced. She eats less, does yoga, and finds the perfect middle ground between firm and soft. Plus, she takes the best care of her skin."
Nino let out a triumphant laugh. "I told you! Itsuki, eat less. Miku, move more. Yotsuba, you spend too much time in the sun; use my face masks."
Rin winked mischievously. "Nino has the best exterior, but the interior might be a different story."
"Eh?" "ovo?"
Nino froze. She had forgotten that the "Deepening Our Understanding" involved internal examinations.
The four lined up on the sofa again, but this time they were in an "M-shaped" leg spread. Nino and Itsuki, the stars of the day, were in the middle, with Miku and Yotsuba on the ends.
It was the first time Nino and Itsuki had been so utterly exposed to a man; both were so embarrassed they didn't know where to look.
"As expected of quintuplets. From the outside, you look exactly the same."
The shape, color, and texture of their "hidden gardens" were identical. Even with his eyes open, Rin couldn't tell the difference just by looking.
"They look the same? What about inside?" Yotsuba winked at Rin. Nino had a bad feeling, which was immediately validated.
"Yotsuba!!!!"
Yotsuba reached over and spread Nino's labia with her fingers while doing the same to herself. Itsuki and Miku shared a look.
"I'll do it myself!" Itsuki cried. Being exposed was bad enough; having a sister do it was worse.
As they opened themselves up, Rin sat on the edge of the coffee table, observing closely. They were only using fingers, so he couldn't see as deep as he could with Mashiro's speculum, but it was enough. The sight of their shamed expressions was far more entertaining than the anatomy itself.
Only Ichika is missing... if all five were in a row, it would be perfection.
After savoring their embarrassment, Rin reached out. "Time to feel the internal differences."
Even though they had been "claimed" by Rin's fingers before, the intimacy still made them flush. Nino and Itsuki weren't "warmed up" like Miku and Yotsuba were the other day. It took a bit more time.
"Ugh... gentle... it's sensitive there... Eek!!!" "Ah..."
The two "virgins" were no match for Rin. Within minutes of his rhythmic stroking, they were fully aroused. Nino and Itsuki arched their slender waists, instinctively trying to escape his fingers, but as their whimpers turned into lustful moans, they began to push back against him, seeking the friction.
Yotsuba watched her sisters melt and began to touch herself, mimicking Rin's technique. She knew this was just the appetizer.
Rin stood up as they reached their limit.
"Stop... stop—Nngghhh!!!!" Nino tried to resist, but it was too late. A pathetic, high-pitched cry escaped her. Itsuki was a bit quieter, covering her mouth to muffle her voice.
It wasn't that Nino was "weaker," but while she tried to push Rin away, Itsuki focused on staying silent. Both of them arched their backs violently as they peaked, but...
"Hmm... Nino wins. You squirted much further."