At Misato West High School, childhood friends Haruka Takayama and Yuu Sonoda find themselves seated apart in their first year. Despite the impending closure of the school, they remain unfazed and determined to make the most of their time together. When Yuu starts forming new friendships, Haruka becomes envious, prompting them to strengthen their bond by sharing a kiss in an empty classroom. As their kisses multiply, they realize their relationship has evolved. However, their newfound romance faces a hurdle when Yuu's disapproving older sister catches wind of their closeness, raising questions about the future of their love.