When Noboru is invited to his girlfriend's house for the first time, he is so nervous that he arrives earlier than planned. However, it is not his girlfriend but her mother, Rina, who is waiting for him there. The two end up waiting together while she goes out shopping. Noboru is drawn to Rina's chest, which exudes sexier and more seductive pheromones than Noboru's. Seeing how cute Noboru is, Rina is unable to suppress the desire that has risen up within her for the first time in a long time, and ends up teasing him with her full adult sex appeal...