The movie is a clandestine love triangle full of desire and anticipation among close friends. Hajime-kun is Kou's boyfriend and also Arina's close friend, but as time goes by, he realizes that his true affection is for Arina, not Kou. Arina, of course, easily notices this, but to avoid breaking her friendship with Kou, she silently expresses her feelings for him. When she learns that Kou will have to go to the city for an internship next month, Arina secretly arranges to meet Hajime to inform him, setting some conditions that if he wants to have intimate relations with her, he must refrain from any sexual activity with Kou, including masturbation, until the end of the month. From that moment on, he completely changes, abstaining from masturbation and always rejecting intimacy whenever Kou feels aroused. Time flies by, and before they know it, a month has passed, and it's now the glorious moment to indulge in the clandestine love affairs of the young couple.