Manga by author Kumakura Takatoshi - Status ongoing

Chibi-chan, a middle school girl, can go no further than 2km from the sacred tree that servers as her town's symbol. That is her "disability".Then one day, a mysterious figure arrives in town to help the girl's wish to leave, her name is Rokushaku-sensei.Guided by Rokushaku, Chibi attempts to bypass her "disability" by going to "Nedoko", backroads that can transport her to another location.However, those places are part of a mysterious world, filled with mysterious creatures.In her desire to see the world, Chibi-chan will have to triumph over these "Nedoko".

The story is a locked-room mystery where 12 kids go into an abandoned hospital to give up on life. In the room where they meet, a boy is already lying dead, and no one knows who he is.(Source: ANN)