Also known as: ニンジャウォーリアーズ, ザ・ニンジャウォーリアーズアゲイン
Beat-em-up series by Taito & Natsume.
Originally an arcade game from 1988, it was ported to various home computer systems in 1989-'90, remade as The Ninja Warriors Again in 1994 for SNES, and remade again in 2019 as The Ninja Warriors Once Again.