Kazuya’s half-assed attempts to “shut Ruka up” go rather badly, as he accidentally cops a feel and also holds her tightly when she falls down a flight of stairs. After saving her, Kazuya cops to Chizuru only being a rental, and in turn begs Ruka to promise via voice recording not to divulge what she knows about them to Kuri or anyone else, for his gran’s sake.
Kazuya assures her this isn’t for him. Even though Chizuru is a rental, she’s “the best girlfriend anyone could ask for” and he doesn’t want her to get hurt. For her part, Ruka is surprised Kazuya isn’t the shallow superficial type she’d expect would normally go for rental girlfriends (ahem…like Kuri). Moved by his honesty and selflessness, Ruka admits she’s a rental too.
Kazuya meets with Chizuru to discuss the emergency. Chizuru finds Ruka on the rental agency website and considers taking action against someone who would “put a fellow pro at risk.” Besides that she recommends they feign ignorance for now and hope she won’t spill the beans.
Without realizing it, Chizuru is at a restaurant lending her ear to Kazuya without it being a formal rental transaction, like it’s the most natural thing in the world. So of course, she immediately cuts their interaction short once Kazuya points that out! Talk about being caught off guard…
The next day while waiting to meet up with Kuri, Ruka intercepts Kazuya instead, asks for a hug of all things, and the two must flee when Kuri arrives, eventually hiding in a lab. Once there, Ruka wraps Kazuya’s arm around her and activates the heartbeat monitor on her phone, which reads 90 bpm.
When Kuri discovers them, Ruka outs herself as a rental, ending the charade and sending Kuri packing looking gray and defeated. Kazuya chases after his friend, leaving up in the air the ramifications of Ruka’s “pursuit” of 90, which has now been achieved thanks to him.
While reporting recent events to Chizuru through her intercom, Ruka tracks him down, takes out her phone and presses “record”, and promises not to tell anyone about him renting Chizuru or about Chizuru’s job…but only if he goes out with her, because she likes him!
In addition to Kazuya being the first man to get her heart rate to rise 90bpm, having heard all of the things Kazuya did for his rental girlfriend’s sake was evidence to her that he’d treat a real girlfriend with even more love and care. With Kazuya facing a decision that will effect her, Chizuru decides to come out of her apartment to discuss things properly.
Ruka takes pride in knowing she’s “gone further” with Kazuya since he never grabbed Chizuru’s boobs, but is flustered and disheartened when she watches Chizuru enter an apparent mere “client’s” apartment so easily, like she’s been in there many times before. Ruka glomms onto Kazuya and refuses to let go, but when he tells her if he an Chizuru can have 5 minutes, she doesn’t refuse.
Here, Chizuru and Kazuya talk things out like the mature adults they are, and exhibit that while they’re not real girlfriend and boyfriend, Ruka is right that they’ve developed a meaningful relationship beyond the transactional. Kazuya is obviously flattered to hear a girl say she likes him, but couldn’t “betray” Kuri by dating her. I put that in quotes because let’s be honest, Kuri was the one lying about having a real girlfriend!
Chizuru’s response isn’t what Kazuya expected: while her end goal will be for him to find a new girlfriend, and this would seem to be a perfect opportunity, she both agrees with his reasoning vis-a-vis Kuri and likely admires him for putting considering the feelings of others before himself. But when he prepares to leap out the window to talk to Kuri in person, Ruka catches him and assumes he’s running from her.
Kazuya falls out of a tree and hurts his back, making it all too easy for Ruka to chase him down and reiterate her desire for them to date. When Kazuya tells her he can’t trample Kuri’s feelings, he ends up trampling on hers instead, and she breaks out into legitimate tears of anguish and desperation. She even correctly points out that Kazuya likes Chizuru…which to which Chizuru (who caught up to them both) reacts pretty predictably.
It’s here where Chizuru, not bad at reading people herself, realizes Ruka’s feelings for Kazuya are most likely legitimate, and so she tells Kazuya to date her after all. Her reasoning is somewhat cynical; while he’s technically giving in to Ruka’s blackmail, dating her is the best way to keep their secrets secret, and they can spare Kuri’s feelings by keeping him in the dark.
Chizuru also makes sure to repeat what Ruka said about it only having to be a “trial period” of dating if Kazuya doesn’t immediately like her the way she likes him. With that, Kazuya asks Ruka to stop crying so he can ask her own and she can accept…and Kazuya suddenly has a real girlfriend. Well, sorta!
As for the root of Ruka’s very real and powerful feelings, we learn about her history of having a weak heartbeat and how it affected her social development and perspective on love. She became a rental girlfriend in hopes that someone somewhere would be able to make her heart beat faster, but it never got anywhere near as high as Kazuya when they first met (79 bpm) or when they were hugging in the lab (90 bpm).
This is actually pretty clever on the show’s part. You cant really say Ruka fell for someone she barely knew, because she doesn’t judge love as a product of familiarity or knowledge, but simply attaining a measurable biological threshold. The question “does an elevated heart rate always mean love” is irrelevant; it means love to her.
This all results in Rent-a-Girlfriend’s best and most complete episode yet, and with Ruka rising to “Best Girl finalist” status. It took what could have been a thoroughly trashy or tacky love triangle scenario, cutting through lies that were getting in the way, and imbuing it with, well, genuine heart. And of course Ruka’s seiyu Touyama Nao is wonderful throughout.