Ponta anxiously awaits the first major event in his high school life, one that will give him the chance to lose his virginity. It is a beach trip with his friends Tarou and Jirou, accompanied by three girls: Emi, Rumi, and Chisa. Partners are chosen by rock-paper-scissors, and Ponta ends up with Chisa, the girl he prefers. His plans fail miserably, however, when it turns out that Chisa is not as willing as he had assumed. So, by the end of the trip—unlike his friends, who tease him about this failure—he remains a virgin. To his friends' surprise, though, Chisa turns around and asks him to keep in touch. Thus begins the romance between the two. Their friendship evolves into love, and like in any relationship, there are a few hurdles to overcome. For starters, Chisa is still very innocent and has good reasons not to hurry their physical relationship as much as Ponta would want to. Ponta, who has hopelessly fallen for her, decides to endure this and help Chisa uncover her womanhood. But then a terrible event happens that will become an enormous obstacle for the couple...