Gennosuke is first seen in the episode "The Big Brawl, Part 2". He retains his persona as a shady bounty hunter, but unlike in Usagi Yojimbo, he is a heavy gambler, as opposed to being a drunkard in the comics. In the Battle Nexus Tournament he defeats an unknown Clawed combatant in Tier 1, an unknown Octopus Contestant in Tier 2 and receives a free pass to the semifinals, where he loses to Kluh. Notably, Gen irritates the Turtles with his behavior, as well as Casey, who he calls "Saru" (monkey or ape). In the episode "The Christmas Aliens", Gen comes to the Turtles' holiday party. In the episode "Samurai Tourist", inspired by a New York City citizen, Gennosuke dons an outfit nearly identical to Rocksteady's in the 1987 TV series.