Kotarou Kawai is the protagonist of the story. He first appeared as a secondary character in the earlier work Houkago Ren'ai Club, where he was depicted as a timid and cowardly individual. In this narrative, he is elevated to the main role and exhibits a more assertive and calculating personality. His actions are largely motivated by a deep interest in unconventional sexual practices, and he possesses a broad understanding of such fetishes, which he uses to orchestrate situations that serve his desires. His interactions with the female characters can develop along two distinct paths: a romantic one that reflects genuine affection, or a path centered on awakening them to his particular sexual preferences, which reveals a manipulative and scheming aspect of his character. This contrast between kindness and exploitation is a defining feature of his personality. His key relationships are with the heroines from the earlier installment, whom he targets as the focus of his plans. His development from a passive, fearful onlooker to a determined and knowledgeable strategist is a central element of his role. His notable ability lies in his detailed familiarity with various fetishes, which he applies alongside deliberate planning to achieve his goals.