Katsuya Maruyama is a middle school student boy full of obscene thoughts. He then meets Tatsuo Shimoi, a single father who moves into the same apartment complex. Tatsuo Shimoi is a bit of an enigma: he doesn't get along with the housewives in the apartment complex and doesn't appear to work. Through his encounter with the mysterious single father, Katsuya grows as a person.

A strange phenomenon takes place. A beautiful flower blooms on a selected woman's body and that flower is called the "Shanidar". When the Shanidar is in full bloom, the flower produces a substance which is then sold at a high cost to develop new drugs. Kenji Otaki works as a researcher at the facility where the Shanidar is grown.