Young Hiroki has been sick all his life. His father died when he was young, and his mother is distant. Even with all of this, he thinks of himself as a pretty normal guy, except that he's completely dependent on his childhood friend, Ayano, who enjoys taking care of him while his mother is away. One day, Hiroki's mom calls and tells him, "I'm hiring a 'private nurse' for you", but Hiroki strongly objects. He doesn't even know what a "private nurse" is, but he knows he doesn't want one ... until she's standing in his doorway, dressed in a sexy nurse uniform. "Hi, I'm Maria. I'm your new private nurse!". She promises to cure Hiroki of his disease within a month. While unbelievable, he tentatively accepts and the treatment begins. Her methods are very "hands on", and Ayano watches with mixed feelings as Maria treats him. As his treatment intensifies so do feelings of love and jealousy. What kind of treatment will Maria use to finally cure Hiroki, and will Ayano just quietly watch and do nothing?