The introverted Yuu Haruna has moved to Tokyo to live with this three sisters after their parents left to work abroad. While passing through the local shopping district, Yuu's eyes are riveted on a TV screen in a store window when a girl comes running up the street and crashes into him. That is how he met the girl who seemed to be wrapped in a summer breeze: Fuuka Akitsuki. Their first meeting goes downhill when Fuuka mistakes Yuu's intentions with the smartphone in his hand, and on top of that, he then finds out that they'll be in the same class at his new school...