椹木 咲麗子

Mayuri's best friend and an antagonist toward Ryou.  For various (obvious) reasons she dislikes Ryou in particular and men in general, and she and Ryou keep meeting despite both attempting to avoid the other. 

In the common route it is revealed she is in love with Mayuri since childhood, as well as being heavily emotionally dependent on her presence in her life.  While she does have a preference for women, she is actually bisexual, though her tendencies/habits born of education and upbringing have led her to fear and hate men. She was ready to give up on Mayuri but Ryou suddenly appeared and when she saw how much head over heels Mayuri was for Ryou, she became unwilling to give up./

Future: In the prologue's future, Mayuri told Ryou that Sakurako just bought a huge isolated mansion somewhere overseas and is still single.