Reimi was a young girl who was brutally murdered along with her parents by an unknown killer. Her spirit remained trapped in the alleyway where she died, unable to move on to the afterlife. She becomes a central character in the story when she befriends the protagonists, Josuke Higashikata and his allies, and helps them to uncover the identity of the killer.

Reimi has a gentle and caring personality and is deeply attached to her home of Morioh and its people. She often provides guidance.