Aoshiba High School[]
Masaya Seki[]
Seki is Kengo's client at the Love agency and a fellow student at Aoshiba High School. Originally they mostly maintain a client-agent relationship but over time, the two become genuine friends. With Kengo sharing his love story for Seki to base his manga on and in return Seki would help Kengo lose weight over the summer.
Mari Maria Winter Nanase[]
Mari is a fellow student at Aoshiba High School. Kengo has approached her in order to gain some intel for advising Seki with his relationship. However when Mari decides to stop pursuing Seki, she switches her attention to Kengo.
Love Agency[]
Kokon Aikawa[]
Kokon is a fellow agent at the love agency. Early on, Kokon has a deep hatred towards him but he does not seem to share the same sentiment, at least not to the same degree. He views her more of a rival within the same agency.
Prior to being love agents, they have been in the same junior high. One time he lent her his history textbook but when she left a drawing of a Kitsune and a Tanuki when she returned it. Since then, Kengo has been smitten with her but he never acted on his feelings.
Years later, Kokon would leave school and they would reunite at the love agency. However she did not remember him at all, this is in part due to his drastically different appearance as well as him speaking in a completely different manner. Nevertheless he still does not believe that he has a chance with her, so he does everything he can to get her attention even if she hates him for it.
Then one summer, while Kokon is away on a trip, Kengo decides to lose weight as part of plan to get her attention. The plan goes well at first but through Mari and Seki's manga, Kokon finds out about his plan. Kokon then confronts Kengo about it and he has no choice but to admit defeat since his plan hinges on Kokon never finding out about it. However to his surprise, Kokon tells him that it is not over, they can be together if he can make her believe in true love.