A tragic car accident shatters the happiness of young lovers Chiaki and Kuon. As 21-year-old Chiaki holds his dying boyfriend in his arms, he is suddenly thrown ten years into the past. He awakens to find himself trapped in the body of a child, yet his adult consciousness remains intact. Determined to alter their grim future, Chiaki seeks out the 28-year-old Kuon, but this version of his lover is a stranger to him—far colder, emotionally wounded, and carrying the weight of a painful past he refuses to discuss. Kuon dismisses Chiaki’s claims that they are destined to be lovers, pushing him away at every turn. Undeterred, Chiaki resolves to slowly break down the walls around Kuon’s heart, hoping to not only save his life but also redeem the man he loves from his past sorrows. The story follows Chiaki’s relentless efforts to earn Kuon’s trust while navigating the complications of his younger body and the mystery of what originally hardened Kuon’s heart.