Wataru Sakurai, an alien from the breasts. However, Wataru was living a frustrating school life where he couldn’t enjoy his big-breasted life, but the situation changed completely when his father was assigned to work alone. Beautiful sisters who moved to the next door … These two familiar people were Fumie Fusano and Yuka, who used to take care of Wataru instead of their mother. Fumie with 100 cm big breasts and Yuka, the owner of beautiful big breasts. Moreover, Fumie can come into contact with big tits day and night as a teacher at Wataru’s school and Yuka as a tutor. Wataru is naturally worried about the valley because of the sweet temptation. Then Yuka smiled. “Do you care about your boobs?”