Katsushika's famous family, the Hanami family, is a family of three generations of matriarchy. In such a house, a boy was born for the first time in 100 years. Its name is "Hanami Mantaro"! Mantaro, who grew up to be more hard-headed than most, has a fiancée! Her name is Satsuki Matsudaira. She was the first princess in 230 years to be born into the Matsudaira family, a prestigious family that has been dominated by men for generations.