Rizu doesn’t know that Uruka likes Nariyuki, and Uruka doesn’t know that Ri likes Nariyuki, but Fumino knows both of those things, and she doesn’t want to rock the boat. However, fate seems to conspire against her, as she trips over her own feet and lands upon Nariyuki in an apparent passionate embrace that Ri happens to witness.
Fumino, convinced Rizu is furious, tries to make it right, ultimately by shoving Nariyuki into Rizu’s embrace; but his head ends up in Ri’s bust—no doubt due to poor calculations on the part of Fumino, for whom math is not her strong suit, as we know. Turns out Rizu only appeared angry because she was squinting due to using a backup pair of glasses.
From there we shift to Nariyuki’s increasingly complex relationship with Kirisu-sensei. When he attempts to rescue a cat from a tree, it ends up jumping off, and Kirisu twists her ankle catching it. Nariyuki helps her get to her apartment, which is an appalling mess.
But since Kirisu is actually a good person (which is why she saved the cat), she makes coffee for Nariyuki and helps him study some history as thanks for his assistance.
While helping her clean, Nariyuki stumbles upon a trophy case packed with accolades from when Kirisu was an ice skater, proving that her desire to steer the girls away from their “emotional” choice of life path is borne out of her having made the same choice when she was younger, and coming to regret it.
Nariyuki tells her that while he appreciates where she’s coming from, he’s decided he’s going to “hold his head high” and “regret it later” with them. It’s only a meaningless, foolish path if they fail, and he can’t yet say that they will.
With that, he takes his leave. When he asks if it’s really okay for a man to have come to her place, she dismisses him as still a child, but once he’s gone, she drops the pretense and reveals she was a nervous wreck, because he was actually the first man ever to be at her place.
One one of their now regular one-on-one chats, Nariyuki tells Fumino about being at Kurisu-sensei’s last night. Knowing it could enrage Rizu and/or Uruka, she drags him to a tree, pushes him against it, and makes him promise not to tell anyone what he just told her.
Naturally, the next time she’s in class, she’s hounded by classmates convinced that she’s in some kind of “special relationship” with Nariyuki, something Nariyuki himself doesn’t deny (since he considers both his tutoring of her and her coaching of him in matters of women to be “special”).
Fumino’s classmates are extremely protective of her, and aren’t about to let just any schmo go out with her, so they send a covert surveillance team to the library where the two are studying, and determine that there’s no overt romantic spark between them, but that they share a “deep trust that transcends the boyfriend-girlfriend barrier.”
Or was she? Fumino may be committed to not making either Rizu or Uruka sad (or mad), but she can’t deny she’s enjoyed all the time she’s spent with Nariyuki, and not just in a tutor-tutee scenario. He’s supporting her wish to pursue her dreams, after all!
When she finally informs Nariyuki of the rumors going around about the two of them, she “jokes” that maybe they should just go out for real. Only judging from Nariyuki’s reaction—and her reaction to his reaction—it sure doesn’t feel like it was a joke. As much as she wants to be above the love polygon, this episode leaves little doubt that she’s one of the vertices.