Japanese developer KAYAC’s viral butt-motion controlled fighting game Ketsu Battler will be getting its largest update ever on July 30. With its title literally translating to “Butt Battler,” the game puts players in a 1-on-1 butt-off against their opponents – and yeah, the idea is that you have to stick a Joy Con in your pants and vigorously shake your ass in order to emerge victorious.
While it was originally conceived as a browser-based minigame for a one-week game jam, Ketsu Battler has grown to be recognized for its competitive depth and was even featured in GBVS Cygames Cup 2026 and EVO Japan 2026 side-tournaments. The game also has a full-blown (and super serious) manga spin-off serialized by Corocoro Comics, and has collaborated with major titles such as Granblue Fantasy Versus: Rising.
Alongside new stages and characters, the update will also add a completely new mechanic dubbed the “Serious Zone” (this is another pun that reads like “Butt Ass Zone” in Japanese). Basically, if you continue to attack more aggressively (if you shake your butt more aggressively), your cheeks will be enveloped in a special aura which enhances both the base stats and special techniques of your character.
The Serious Zone will become much easier to trigger as the match drags on, or if you’re being continuously cornered by your opponent, opening up the way for some new butt strategies. It will be interesting to see how this will reflect onto competitive play as well, given that having good butt stamina is key to overthrowing your opponent. Tiring your enemy and then going all in on the twerking might be crucial for coming out victorious.
Additionally, Ketsu Battler’s will receive a zero-gravity stage, a stage where the Serious Zone is always activated, and a stage where the Serious Zone does not get triggered, giving players more options to customize their experience.
Ketsu Battler is available for the Nintendo Switch and Switch 2.
