"Jun Aiba, will you give me your life?". On the last Christmas of his high school life, Jun Aiba, who is having a hard time living, makes a deal with a woman who calls herself the God of Death. In exchange for his life span, Aiba obtains a watch that can rewind time, and uses the power of the watch to realize his ideal life. Aiba tries to spend the remaining three years of his life without any inconvenience, but his life changes drastically when he interrupts the suicide of a girl who was supposed to die. Aiba decides to keep interfering until Tsukimi Ichinose, a girl who wants to die, gives up on suicide. He spends his days struggling against Ichinose, who refuses to give up on her suicide.