A social worker at the Ministry of Health, Labor and Welfare. He manages the Yukari couples alongside his partner, Kagetsu Ichijou. Motoi is currently married, but he's not happy with his partner and hasn't called his wife in two years.

Spoiler

Motoi and Kagetsu attended Kasugayama High and they broke up the day of Kagetsu's 16th birthday when she offered to reject her assigned partner if Motoi committed to marry her. However, with them being so young, and him not confident, he didn’t follow through and refused-- a decision that he still regrets to this day.