Set in Kyoto, Japan, a love story takes place between Hajime and Reika. Hajime is a handsome young man, who is usually a second quicker than everyone else and straightforward. He works at the post office. Reika is a young woman, who is usually a step slower than everyone else. After Valentine's Day, Hajime wakes up and is unable to remember what happened that day.
After participating to a previous show where they have to bet or be challenged to any kind of competitions, the losing members of the Gaki no Tsukai are selected to spend 24 hours in a setting which they have no knowledge of the theme nor the course of the events. They are exposed to various absurd and crazy situations nonstop for 24 hours and must refrain from laughing. If they do so, hang-men appear and hit the rule breakers with a weapon (the weapon varies every year).
