Ken Sugisaki is the male student council vice-president at Hekiyou Academy, having earned his position through academic achievement after dramatically improving his grades from nearly the lowest in his year to the very top. This effort was driven solely by his desire to join the student council, which is typically composed of popular female students selected by vote.

His outward behavior is predominantly perverted and eccentric; he often openly declares his intent to make the female council members his harem and frequently engages in behavior that results in physical retaliation from them. This persona is a deliberate act. Despite his lazy and carefree exterior, he is an exceptionally hardworking individual who single-handedly completes all the student council's paperwork after hours so the other members can enjoy their time together.

A significant past event shapes his motivations. During middle school, he was ostracized and bullied by his classmates due to a perceived two-timing scandal. This incident involved his stepsister, who fell into depression after he began dating a childhood friend, and the subsequent breakup when he prioritized caring for his stepsister. He internalized deep guilt for this period, even requesting to be bullied, and it led him to develop a "Stepford Smiler" defense mechanism to hide his emotional trauma.

His drive to create a happy environment for the student council stems from encounters with each of the four female members before he joined. He met each girl in a different season of his first year of high school, and each interaction positively influenced him and helped him recover from his middle school trauma. Joining the council and striving to make all its members happy is his primary method of repaying them and atoning for his past.

His character is defined by the contradiction between his stated harem-seeking goal and his deeper, selfless desire to ensure the happiness of those around him without expecting anything in return. This is evidenced by his surprise and distress when a council member actually shows romantic interest in him, suggesting his perverted act may also be a subconscious strategy to avoid romantic entanglements and prevent a repeat of his past failure. His complex personality leads others to describe him as a "Bunny-Ears Lawyer" for combining his ridiculous behavior with genuine competence and a "Chivalrous Pervert" for his underlying noble intentions.

A central trivia point is his narrative pattern of beginning each episode with behavior that exasperates the council but concluding each episode by revealing his serious, dependable side, which makes the other members grateful for him. His relationships deepened in the sequel series, with the female members becoming less hostile and more accepting of his presence, acknowledging his genuine care for them. He is currently dating the student council president, Kurimu Sakurano.