Koyomi Yoimachi

She is a very cheerful girl, but she also has a double personality. Unlike Koyomi's innocent and sweet exterior, her other personality, "Yomi", is without reserves and is usually fondling Michiru, despite the latter's unwillingness to do so. It appears that Michiru is the only person able to awaken this alter ego of Koyomi's, merely by kissing her or simply calling her by name. In chapter 65, Yomi tells Michiru that she is actually a boy; this is hinted at in earlier chapters when Michiru learns that Yomi was made from the spirits of the slaughtered boys from Yoitsuhara clan.