Ah yes. Classmates that don't actually care about you. I wonder how fucked up the author's life is if the author is projecting some part of his/her life to this manga.
Y'know, if he knew that the reason why Ruka likes him is because of her heart condition. I think he should stay with her if she doesn't like Ruka. If she's always with him, she will no longer feel as excited every time she's near him.