The protagonist of the tale, simply referred to as "I," experiences an endless cycle of reincarnation. The narrative takes place in a different universe where people are free to select their next form. However, the waiting list for popular roles, like "Demon King" or "Hero with Cheat Skills and a Harem," has reached 50,000 years due to a recent spike in applications.

The protagonist decides to repeatedly reincarnate into increasingly strange forms because he refuses to wait. These roles include the rib of a hero in charge of a harem, a hermit crab, a vegetable, and even an explosive used to blow up blissfully happy couples.