The show commits to its premise with zero irony. Keijo treats competitive butt-fighting like it's legitimate sport drama, complete with training montages, rival backstories, and genuine stakes for a character who just wants to escape poverty. That absolute sincerity is where the comedy lives, not in winking at the audience about how absurd it is. You're watching someone train her glutes with the same desperation a shonen protagonist trains their fists, and the show never breaks character to make fun of itself. It's funnier because it means it.

Nozomi Kaminashi grew up in a poor family and wants to earn a fortune through Keijo, a bizarre sport where competitors stand on floating platforms and knock opponents into the water using only their butts and chests. It sounds ridiculous because it absolutely is, but the sport draws millions of viewers and the prize money is serious. A former gymnast with natural balance and flexibility, the 18-year-old enrolls in a Keijo training boarding school after high school. She makes a strong impression in her first tournament, then meets friends and rivals as she works her way up the ranks and finds that the road to stardom tests her body and spirit alike. The ridiculous premise lets this comedic, fan-service-heavy sports story lean into slapstick humor and over-the-top action.