Mayuka Korenaga

Mayuka Korenaga (是永 麻由香, Korenaga Mayuka) is Daiki's older sister. Her existence is also kept low profile until a certain point where it is found that she is actually the girlfriend of the unobtainable Ren Ichinose. She has a job which is in the modelling business which she pursued for what she thought was Ren's sake and she is currently studying for entrance exams to university. As the series progresses, she becomes wary of Ninako's relationship with Ren but remains friendly toward her. She eventually realizes how much her relationship with Ren is strained: she is almost always busy and has to cancel their dates. In chapter 19, she breaks up with Ren because she now knows that Ren is in love with someone else and she doesn't want Ren to continually repress his feelings just for her. She acknowledges that nothing will ever stay the same, as she herself has changed, and that before she didn't want Ren to change and leave her.