Redeem: Only One Forever vol 1 back

After 21-year-old Chiaki watches his boyfriend, Kuon, die in a tragic accident right before his eyes, he suddenly wakes up to find himself flung ten years into the past! Now stuck in a child’s body, he tries to convince Kuon that he’s his future lover, but 28-year-old Kuon is a much colder and more pained man than the one he knew. But no matter how hard Kuon tries to push Chiaki away, Chiaki won’t give up until, step by step, he works his way into Kuon’s hardened heart once more...