After what went down in the chairman’s office, Yuzu is now afraid to even face Mei, and so retreats to the safety of Harumin’s traditional house, where she lives with her grandmother. Harumin really shines as Yuzu’s dependable and caring friend, while professing she doesn’t mind because Yuzu is so fun to hang out with. But in the night, Yuzu is wide awake, and her mind is racing. So is Mei’s, as she lies alone back home.
Vice president Momokino Himeko is an apparent witness to Yuzu and Mei’s little tryst, and when Yuzu spots her heading her way, she bolts. When she finally stops, Himeko asks her about the chairman’s office, and Yuzu agrees to meet her outside of school to discuss it.
The meeting spot is a very hoity-toity tea room where Himeko is all dolled up like, well, a doll, and she doesn’t mince words: she wants to know what happened in that office. Himeko, you see, has known “Mei-mei” for ten years, and is her closest and most loyal and dedicated friend. She was by Mei’s side when her father left her.
Translation: she has, and has always had, the hots for Mei, big time, and Yuzu is in the effing way, and needs to eff off, though she frames it as not wanting Yuzu to continue hurting Mei. However, when Yuzu leaves the tea room and bumps into Mei by chance, Mei calls her “Yuzu” and asks when she’s returning home.
Himeko thus learns for the first time that the two are sisters and living together—everything she probably wanted and believes she deserves—and she’s devastated.
Yuzu has trouble reading Mei on their trip home (as usual) but presumes she’s not too mad, and asserts that her usual quietness is actually comforting. When Mei senses Yuzu wants some kind of closure, she kisses Yuzu back, but that one kiss is all Yuzu gets; Mei goes straight to sleep.
The next day, Himeko, feeling threatened further when Yuzu intrudes on her “commute time” with Mei, makes a drastic move, assaulting Mei in the student council office by biting her ear, groping her above and below, and kissing her.
It’s harsh, callous betrayal, reinforced by what we know of “Hime” thus far: she pretends to care about Mei, but really only cares about herself, and wants to ensure Mei remains “hers.” She reports her line-crossing to Yuzu, and when Yuzu feigns ignorance of her feelings for Mei, Himeko asks her for her blessing, calling her “onee-sama.”
Himeko may be a stickler for the rules at school, but when it comes to Mei, she’ll do ruthlessly whatever it takes to keep hold of her prize. Yuzu must either fight back or get left in the dust. There’s also the matter of protecting her emotionally vulnerable little sister from a friend who has turned predatory.
Why do I regard Himeko’s jumping of Mei so differently from Yuzu’s? Two reasons: First, Mei started this…thing with Yuzu; Mei admitted as much to Yuzu. She did no such thing with Himeko.
Second, Yuzu regrets jumping Mei, and knows it was a moment of weakness; Himeko has so far shown no remorse; only contempt for Yuzu, intense possessiveness of “Mei-mei”, and utter disregard for her feelings I’m hoping her transgressions don’t go unpunished.