Ace pilot Trava and his personal mechanic buddy Shinkai, on their way to mark an out-of-the-way planet, pick up Mikuru, a girl with no memory. The three are about to discover that the planet is more than it seems.

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).