Kouichi Sanada wakes from a dream where his younger self was crying. When he goes to answer the door, he finds a beautiful woman standing in front of him. She quickly enters while reacquainting herself with things in the house, and even enters the shower. A confused Kouichi tries to remember if he knew a girl like this in the past, when his friend Kazuki Aihara comes in. A misunderstanding is caused when the girl comes out of the bathroom, but she suddenly realizes who Kazuki is. Kazuki also realizes who the girl is: his childhood friend Mao Mizusawa. Finally realizing this, Kouichi welcomes Mao back. When Kouichi’s mother begins talking to Mao about her living in France, Kouichi notices how much Mao has changed. The story then continues with them going to the same school. Many relationships are formed with different people during their school years but always thought to be a mistake as Mao realizes her true feelings toward Kouichi while Sakino and Futami develops feelings for Kazuki. Telling him of her feelings gets him confused as he always thought of her as a sister, always thinking of her gets Yuumi worried as he never seems to be focused. As it is nearly time for Yuumi to move away, she puts on a brave face so she doesn’t upset Kouichi while he is still in his endless daydream. Nearing the end, Kouichi finally realizes who he truly loves and tells Y?mi before he heads out to find Mao. Having found her, tells her of his feelings and it finishes with a kiss.