The story revolves around three siblings - Natsuki Enomotos confession rehearsals with Yuu Setoguchi, their younger brothers Kotarou and Hina struggle to confess their own feelings of love. Despite her initial confusion upon meeting Koyuki Ayase in middle school, Hinas heart is captured by his warm smile, leading her to fall in love for the first time. As she chases after her brother Yuu and her crush Koyuki, Hina enrolls at Sakuragaoka High School, where their feelings of love become intertwined with those of their friends. Kotarou, unaware of his own feelings for Hina, remains determined to keep her smiling, while Hina hopes to confess her love to the tender-hearted Koyuki. The story is followed by Suki ni Naru Sono Shunkan wo., which explores how their youthful love creates new relationships but also poses a threat to existing ones.