A reverse comedy that tells the story of a perfectionist assassin who falls and hits his head in a sauna, giving him amnesia. When a down-and-out actor switches locker keys with him, they switch lives until the hit-man, who soon becomes an action hero on TV, starts to remember things.

Katsu (Mitsuko Baisho) is a 73-years-old woman. She often makes trouble with her biting remarks. While raising a daughter alone, Katsu was unable to live the life she wished for. One day, Katsu goes to a photo studio and takes a picture. She leaves the photo studio, but finds that she is now 20-years-old (Mikako Tabe) again. Katsu changes out of her grandmother clothes, picks out a more youthful style and names herself Setsuko Otori. Later, Katsu decides to take part in a singing contest held in a shopping district. Her singing fascinates the audience and she wins the contest. Katsu begins to move closer to her past dream of becoming a singer.