Natsu, who is sober and reserved, has a shy personality that cannot be rejected. One day, he confesses to Sato, who is in the same department, and they start dating. Natsu, who usually wears plain glasses and has messy hair, is noticed by the manager when he sees Natsu's skin color, and excessive sexual harassment begins the next day. Natsu, who cannot be rejected, gradually develops breasts and immediately falls into pleasure when she is trained on her constitution.