Ameku Takao is a genius doctor with a knack for solving all kinds of difficult cases. When a man with blue blood is brought to Tenikai General Hospital—where Takao is the vice-director—after having his leg bitten off by a large beast, she starts investigating the intriguing case with the aid of her colleague, Takanashi.

Several hospital staff report an angel in one room, and a pediatrician asks Takao for help with three children.