The day before her 18th birthday, high school senior Nino is proposed to by her extremely popular childhood friend Ichi, whose face is a national treasure. When she refuses to believe Ichi's feelings for her, who has grown up with her like a brother and sister, he says, "Let's experiment to see if we can become a love object"...? Since then, he has been hugging and pampering her everywhere, and scheming to make Nino his sole slave...? The drowning (love attack) and playing lover that is accelerating more and more, Nino is at the mercy of...?!