The quirky 1-on-1 motion-controlled fighting game Ketsu Battler has made significant strides since its December 2024 launch on Nintendo Switch. Despite its unconventional concept of inserting a Joy Con into one’s pants to control fighters armed with swords in their buttocks, which initially seemed like a fleeting joke, the title has since gained recognition for its competitive gameplay. It has even been featured in side-tournaments at the GBVS Cygames Cup 2026 and EVO Japan 2026.
Notably, Ketsu Battler forged an official partnership with Granblue Fantasy Versus: Rising in January 2026, welcoming Beelzebub and Narmaya as guest fighters. In an interview with Famitsu ahead of Ketsu Battler’s major Ver 2.0 update, the game’s developer TomozoP (affiliated with KAYAC) discussed the origins of this collaboration.
According to TomozoP, the proposal arrived “completely unexpectedly,” which he considers a stroke of luck. Tetsuya Fukuhara, the creative director behind the Granblue Fantasy franchise, contacted his team specifically requesting Beelzebub and Narmaya from Versus Rising to appear in Ketsu Battler. “Initially, I thought it was a prank,” TomozoP recalls, “but as talks continued, it became evident they were serious. That’s when I realized, ‘Oh wait, they weren’t joking’ (laughs).”
Upon inquiring about the circumstances, TomozoP discovered the connection involved voice actor Hiroki Yasumoto, known for roles such as Street Fighter’s Guile and BlazBlue’s Azrael, who had played Ketsu Battler during a live stream. The story takes a surreal turn: “I’d posted on X expressing my delight as a long-time BlazBlue fan that Yasumoto had tried our game. Then Toshimichi Mori, the former BlazBlue producer, quote-retweeted my post. That’s how Mori first heard about Ketsu Battler. He later invited Fukuhara to play it together… which is reportedly how Fukuhara discovered Ketsu Battler.”
While TomozoP was naturally thrilled about the collaboration, he was most amazed by the series of coincidences that made it happen. “Those kinds of character reveals and surprise announcements are something every game developer dreams of experiencing at least once. I never thought Ketsu Battler would have a moment like that.”
It’s worth noting that Ketsu Battler originated from a browser mini-game TomozoP created for a one-week game jam. He later entered the project into a competition hosted by CoroCoro Comic and won, securing support to publish a full console game from the publisher. Given this humble beginnings, Ketsu Battler’s ascent in popularity among Japanese fighting game enthusiasts is all the more remarkable.
Ketsu Battler is available for the Nintendo Switch and Switch 2.