Ieyasu Kikuchi stands as Takumi Tsuzuki's closest male friend and classmate. A dedicated full-time otaku, his world centers entirely on anime, manga, galge (erotic computer games), doujin, and related pursuits. He expresses zero interest in real-world women, with a single, profound exception: Takumi's older sister, Otome Tsuzuki. After she saved him from delinquents, he reverently calls her "Master," the sole real woman whose existence he fully acknowledges.

Physically, Ieyasu sports brown hair with bangs hanging on either side, blue eyes, and round-shaped glasses. He habitually provokes Fumino Serizawa with his comments, often requiring Otome's intervention to shield him from Fumino's violent reactions. He constantly draws parallels between real-life situations and scenarios from galge. Chronic sleep deprivation plagues him at school, a direct result of staying up late to watch anime broadcasts live and stay current. Despite his proclaimed disinterest in real women, he feels compelled to secretly observe attractive females like Fumino or Nozomi during private activities such as bathing. He also suffers from severe aerophobia; panic attacks during flights overwhelm him unless he watches new anime.

Ieyasu maintains a collaborative connection with Chise Umenomori, working with her on plans fueled by their mutual passion for anime and manga. Chise leverages her wealth to offer him desirable items, fostering their ongoing interactions.