Kazuya, after dealing and closing his relationships with the other waifus, and right after helping in a short arc in which Kuri shines for once and makes Ruka fall for someone genuinely and not bc of those retarded dokidokis, with a tricky advice from Yaemori and a final encouragement from Kibe and Kuri, rents Chizuru for a last time and only an hour. He gives the mandatory fee and goes to the aquarium, being strangely silent and answering with monosyllabes everything she says. By the end of the date, he refuses the handholding, says it's the last time he'll rent her and bids her goodbye and good luck. Once he's out, Chizuru ends puzzled by his behavior.
Later, in her apartment, Chizuru sees an anonymous 5 star review in diamond with a paragraph akin to "i never expected to say this, but all this time i knew i became a stupid man that fell in love with the perfect girlfriend, even though it was all an act from her, like a fish, i ended up eating the bait". She realizes the review was from Kazuya (bc of the fish), realizes every time he talked about his ideal girlfriend, and the time he said he wanted to introduce the right gf to his family, all that thime he was talking about her (as both her Mizuhara and the Ichinose persona), starts to cry because of being stupid at not realizing before and looks out for him. She ends up finding him in the park he gave Ruka the ok for the trial relationship and, looking down and hiding her eyes, demands him what did he mean with that review, visibly shaken and angry. Kazuya, after sperging out a bit bc he thinks she is holding a grudge against him, but cooling down and getting a newfound confidence and sense of awareness after remembering the words from his friends, answers her he was being really serious with what he said in that review and flat out says i love you, but also says he understands if they can't be together because she has her dreams and a promising future and he is still stagnated in a fucking personal limbo and that could make things not work well for them. He bids her goodbye again, but is stopped by her. She apologizes for being stubborn af, she admits she was also being an idiot for not realizing at time she also fell for an idiot who ended falling in love for a renkano. He knows she is talking about him, but decides to ask her if she's being sincere for real or she's just acting like she always do... Chizuru gets furious moves her head up, and with tears in her eyes, she shouts she's also serious this time, that she doesn't care if he is in a fucking limbo like he said before, as she says that with him constantly fighting to improve himself and be worthy enough for his loved ones is enough for her and that it's not the first time she fails as a professional, but it's okay if he doesn't believe her, bc of what happened before. Kazuya surprisingly hugs her, thanks her for being sincere and says he's really happy for hearing that... but before asking her to date for real, he recieves a distressing LINE message from mom that says Nagomi died a while ago from a stroke.
Last chapter is a 1 week timeskip with Kazuya visiting her granny and lamenting he couldn't properly introduce Chizuru to her for real, but hopes granny looks out for him from wherever she is now and gets happy for his incompetent son finally going steady for real. Chizuru joins to pay respects to his granny. Once they are out, she questions him what was he wanting to say the day he confessed before getting interrupted by that message. He casually says he was asking to have a quiet real date the next weekend, but with the real her, she says fine by her, as she is officially out of the rental business after quitting from Diamond a day before kazugranny was buried (the wake lasted 2 days), while walking to their apartments, they see Ruka with Kuribayashi hand by hand, but decide to not pester them, Kazuya casually says he can't help, but feel genuinely happy for Ruka being in a honest relationship. Once on his flat, Kazuya tries to think what would be the appropiate activities for a quiet first real date, but decides to go with the flow in the end, or else he'd fuck up for real. Skip to the weekend and Chizuru comes late by 10 minutes... but with the perfect gf persona. Kazuya asks her why is she going as Mizuhara, as he asked for the real her, but she cuts short by asking him if isn't ok for him if Kazuya's gf goes dressed as how her bf wants. Kazuya says he can't help it and they go hand by hand to their first real date. End.
It might be the best full circle, although cliche, end if it finishes as how it started, but with a twist.