You're walking along the school corridors when you notice a strange girl.

She's watching something, no, someone! It seems strange to you, even creepy, and you wipe your eyes well, but when you open them, the girl is no longer in the place where she stood. Wait, where is she..?

"Hello!" It comes sharply from behind your back. Ryoba's voice is kind and sweetly mysterious. There's something wrong with her. "I'm Ryoba Aishi, and you..?"