Despite his mundane appearance and personality, Koutarou is a regular high school instructor known to be insipid. Meanwhile, his father-in-law, Koushi, is over 50 years old but still exudes charm. Sayotani, Koutarou's pupil, is a youth with striking looks who goes from one romance to the next. Despite their age differences, these three individuals find a connection through Koutarou.