Nurse Yuu no Muma Sensen

"Nurse Yuu no Mumasensen" is an adventure game with a rather cryptic story. The player controls a young nurse named Yuu, who finds herself near a secluded military hospital, unable to understand whether she is dreaming or not. She then begins to work at the hospital, becoming more and more intrigued by the events happening in it.

[From Moby Games]