Takumi Onodera possesses dark brown hair and blue eyes. His quiet life is upended when his father unexpectedly announces that Saori and Yui will become non-biological residents in their household. This alters his previously uneventful existence.

Takumi first meets Saori when she helps him after a bicycle accident, though he doesn't learn her name. He later discovers her identity, and the new living arrangement with Saori and her younger sister Yui, upon her arrival at his home. Takumi develops an intense attraction to Saori, determined to prove himself worthy and earn her favor.

Saori's behavior complicates his efforts; her initial helpful warmth from their first meeting shifts to a distant, dismissive attitude within the household, creating tension. Simultaneously, Takumi's long-time friends, Mizuki and Satsuki Kirishima, unexpectedly express romantic interest in him, an unforeseen development.

Takumi navigates complex emotional dynamics involving Saori, Yui, Mizuki, and Satsuki. While his primary focus remains pursuing Saori, he does not actively resist the romantic advances from his friends. This places him in a challenging position, caught between conflicting feelings and the attention of multiple individuals.

His character arc centers on adapting to the altered domestic situation while managing his attraction to Saori alongside the shifting dynamics with Mizuki and Satsuki. His persistent attempts to connect with Saori continue despite her changed behavior, even as the evolving relationships with his friends add layers of emotional complexity to his daily life.