Dupa ce te uiti la toata seria Higurashi nu afli foarte multe despre Hanyuu decat ca e un sacrifice from the past, that she's Oyashiro-sama and she is for some reason "helping" Rika. Si la sfarsit iti mai transteste si a grown up version of Rika si se termina. The answers are in Umineko, unfortunately not in the anime, just the VNs. So here's a short explanation: Hanyuu's real name is Featherine Augustus Aurora, she's an immortal witch with power that pretty much equals God, her hobby is "playing" with humans and driving them insane, in this case Furude Rika.