The manga and anime, from Studio Trigger, creators of Kill La Kill, that blew minds and slayed ninjas!

In the cyberpunk metropolis of Neo Saitama, Kenji Fujikido is an average salaryman whose wife and children are suddenly assassinated. Tracking the murder back to a ninja, Fujikido trains to seek vengeance initially on those who murdered his family, but ultimately on every ninja on the planet...