You're watching a show that commits harder to being dumb on purpose than most anime commit to being smart. The animation looks like someone fed a light novel to a malfunctioning render engine, except that's the entire joke, Ninja Slayer is roasting the industry that made it while your possessed salaryman screams "ABBAH" and murders syndicate goons with the energy of a man who just discovered both vengeance and comedic timing exist. If you can sit with intentional jank and repetition that's funnier the tenth time than the first, this is the only anime making fun of itself while genuinely respecting the absurdity it's built on.

Kenji Fujikido is an ordinary salaryman until a turf war between ninja kills his wife and child. As he nears death himself, a mysterious ninja soul called Naraku Ninja takes possession of him, and he survives as Ninja Slayer, a reaper bound to destroy evil ninja in a private war of revenge. His fight unfolds in Neo-Saitama, a near-future city where cybernetics and electronic networks rule and ancient ninja souls have returned to its shadows. There he faces the ninja of the Soukai Syndicate in deadly combat. Expect a cyberpunk action series built around a lone avenger.