Yuuri Senya

The ghost girl is an unnamed girl who appears in Toaru Kagaku no Railgun Gaiden: Astral Buddy. Supposedly a ghost and suffering from amnesia, she seeks Hokaze Junko's help in finding out who she was.

Background
The ghost girl's background is unknown, as she doesn't have any memory of who she is, though she suspects that she is likely someone who has died.

Abilities
The ghost girl displays a number of traits which are commonly associated with ghosts, including and the ability to  people and animals.