Who killed Hanyuu - Minna Inakunatta

Ever wondered why Hanyuu had no body in Higurashi no naku koro ni Rei but not in Kai? The reason is that she was killed. Who killed Hanyuu? I don’t who did it but you must figure it out. But there are a few rules to the game. 1. Neither Takano or the organization of tokyo did it. 2. She was last seen by Rika alive when Hanyuu said that she wanted to go back alone. 3. Any anime can be used to as suspects in the muder(try to use higurashi character’s its more fun that way) If you figure out who killed