シグマ

New character introduced in the PSV version of the trilogy.Suddenly appears in front of the protagonist, a girl who hides her face with a veil. Claimed to be a witch who came from another world and is looking for a thing. Her power as a witch seemed to be immature, she can be only seen by the protagonist. Often talk to the doll held by her hands."...Shishigatani Ushio-san, yes. This person is... seemed to be cold at the first sight, but..."[Translated from the official PSV Website]