"Please let me take responsibility!!" Rui, a pharmacist, is a sexual pleasure seeker. One day, he brings a completely drunk virgin, Takanashi, back to his place. Although they were extremely compatible sexually, Rui leaves the hotel, thinking it was his usual one-night stand. However, to his surprise, Takanashi says, "It looks like I fell in love with you, Rui-san.", and begins his aggressive pursuit. Despite being a bit put off by Takanashi's almost-stalker-like affection, which includes getting a part-time job at Rui's workplace while constantly checking up on him, Rui's heart begins to waver as he sees Takanashi's sincere devotion to him...