Bobobo-bo Bo-bobo (2005)

S01E30 Revenge is a Dish Best Served Cold with Shitake Mushroom Sauce.

Just as the battle for the title of King of Wiggin Specialist wraps up, a loud-mouthed ninja assassin appears, ready to challenge Bo-bobo on behalf of his terrifying master, the OVER of the Baldy-Bald Big Four! After Bo-bobo and his friends navigate through the ninja's clumsy tricks, they’re sent off to face a flying warrior obsessed with ducks, along with a Serviceman dangling precariously. But that’s only the beginning; they must also confront the Ultimate Five Assassins, starting with an unexpectedly playful little girl!