鳥海 有栖

A girl that appears in Tooru’s dreams. She claims to be able to wander from dream to dream, but there’s no way to prove it. Her words and actions are often frustrating, because she seems to know various things but then it turns out she really doesn’t. But it’s at least certain that she’s an ally of Tooru’s... Probably. She is never really on her guard. [From Mangagamer]