Takumi Onodera is a high school student with dark brown hair, blue eyes, and a lean build. His life is drastically altered when his father unexpectedly introduces two new female members to their household: Saori and Yui Shirakawa. Though not biologically related or formally adopted, Saori and Yui move in, fundamentally changing Takumi's domestic world.

Takumi first meets Saori when she kindly helps him after a bicycle accident. However, upon cohabiting, Saori displays a consistently cold and dismissive attitude towards him, creating a jarring shift from their initial encounter. This motivates Takumi to actively seek Saori's approval and affection, viewing her as his primary romantic interest despite their complex living situation.

Simultaneously, Takumi navigates his long-standing friendship with neighbor sisters Mitsuki and Satsuki Kirishima. Both unexpectedly develop romantic feelings for him. While Takumi engages physically with Mitsuki, Satsuki, and Yui, these interactions remain secondary to his emotional pursuit of Saori. Juggling these multiple affections creates persistent internal conflict for him.

The resolution centers on Takumi's sustained efforts to connect emotionally with Saori. Eventually, her demeanor softens, leading to a mutual romantic acknowledgment between them, concluding his central character arc. His personality shifts from initial passivity to determination in pursuing Saori, though his divided focus causes inconsistency.