Yamibo - Darkness, the Hat, and the Travelers of the Books (2003)

Cast: Mamiko Noto, Sanae Kobayashi, Reiko Takagi, Kikuko Inoue, Romi Park, Shin-ichiro Miki, Takashi Nagasako, Rie Kanda, Fumihiko Tachiki, Ai Shimizu

Hatsuki is a highschool student living with her sister, Hatsumi, who she has a huge crush on. On Hatsumi's 16th birthday, she is suddenly surrounded by a green light and disappears in front of Hatsuki…