Actually, I found it kind of annoying that Kokoro did that. Might was well tell Kippei what it is then having him be worried or depressed about being dumped and not knowing why, I mean even if she did that because she thought she didn't want to give him more problem or whatever because he takes care of Yuzuyu, still kind of obvious that he would not just go "oh ok, you dumped me, bye bye" he will want to know why, and I have a feeling it won't be something that would totally break them up so she should of just told him...she really needs to learn to say what she really means/wants -.-