Ninja SlayerNinja Slayer.

Ninja Slayer (Japanese: ニンジャスレイヤー, Hepburn: Ninja Sureiyā) is a novel series styled as a work by American authors Bradley Bond and Philip "Ninj@" Morzez, who have authorized Honda Yu and Sugi Leika to translate it into Japanese. Enterbrain published the first Japanese version in September 2012, with illustrations by Warainaku. Sixteen novels have been released as of June 2016.