Based on a game by M no Violet. Sequel to Night Shift Nurses 2.

Sora was lying in front of a hospital. He was seriously injured, and when he was about to die, a nurse, Yamami Yu, helped him. He was sent into an emergency ward, and he met a beautiful woman, Mikage Reika. She was a director of the hospital, and she asked him to become a test subject. Because he didn't have any relatives, he accepted it. Then, Yagami Yu was supposed to take care of him. Since that day, his fate had changed a lot.