Kazuya is convinced Mami is going to let him have it now that she knows Chizuru was a rental girlfriend, but to his shock she’s nice. She’s worried she “pushed him” to this, something he denies, and says instead it was a kind of “social experiment”.
Mami leaves him saying he shouldn’t waste his time and money on fake girlfriends, but doesn’t believe a word he says otherwise. She knows something’s up, and while she calls him a loser, she wouldn’t be bothering with him at all if she didn’t still care about the lug.
From there, it’s a Ruka episode, which is always a delight because how there’s a simplicity to her dynamic with Kazuya. He fully appreciates what a stunningly cute young woman she is, but doesn’t have feelings for her the way he does for Chizuru, so even though she’s willing to be his real and actual girlfriend, it just doesn’t quite feel right for Kazuya.
That said, Ruka has the time of her life shopping and cooking curry wth expensive soft-shell turtle (a known aphrodisiac) for the one she loves. She clearly prepared for this, and the show doesn’t cop out by making her a terrible cook. The curry is damned good, and also works downstairs, if you catch my drift.
Kazuya knows he should be perfectly content eating, watching TV, and eventually getting down to some hanky-panky Ruka has already made clear she’s ready for whenever he is. She even sends a text saying she’s staying at a friend’s so she can spend the night, which she sees as only fair.
After all, she let Kazuya go on rental dates with Chizuru. If Kazuya is going to allow her to frame their relationship as near-as-makes-no-difference legitimate, that means he owes her. Mother Nature tends to agree, sending a dousing typhoon to cancel all the trains and keep Ruka right where she is.
After she takes a shower and changes into his baggy shirt (and not the pants he offered), Kazuya can already barely take it, so when he’s in the shower he rubs one out for some “clarity” on the situation. Not helping matters is how loud Ruka tends to be with Chizuru right next door. Also not helping matters is when Ruka digs through her purse and a condom pops out…”just in case.”
That night he sleeps on the floor of the kitchen, worried that he’s caused Ruka to act this aggressive to compensate for the stress his stuff with Chizuru is causing, but he’s focused on simply getting through the night. That becomes incredibly more difficult when Ruka snuggles up behind him, giving him the chance to do whatever he wants, which is what she wants too.
It’s the sight of the phone case Chizuru gave him that stops him from turning over. But when Ruka starts going on about how he must not think she’s attractive enough, or that she’s being too clingy or a pain or a bother, he gets up and sets her straight: he’d never cal her bother, she’s so cute he can’t take it, and hearing her say he likes her makes him want to jump for joy.
He just doesn’t want to make a “terrible mistake”. Ruka, understanding, retreats to her bed, but falls asleep happy thanks to all the nice things Kazuya said. The next morning, before kissing him goodbye, Ruka says those works made her feel like she could stay by his side, so she will. She also makes sure Chizuru overhears her yelling about their amazing night together, which Chizuru definitely overhears from the other side of her door.
I know Chizuru is the girl Kazuya is supposed to end up with, and he clearly has strong feelings for her, every time Ruka gets her chance (which is rare) to offer a viable alternative route, she sure doesn’t squander it. The production also doesn’t skimp on the detail needed to up the intimacy levels of their scenes, and Touyama Nao’s warm, singsongy, expressive voice fits Ruka’s energy perfectly.