Ninja Royale: The Mightiest Ninja Across Time

Read manga Ninja Royale: The Mightiest Ninja Across Time / ニンジャロワイアル～時を超えた最強の忍者～
Ninja — those superhuman beings who honed special combat abilities called ninjutsu (ninja skills), operating in the shadows of history. Gokō, the strongest ninja of the Warring States era, reincarnates into the modern world after 500 years and savors the peace of contemporary life… but lurking in the shadows of modern society are evil ninjas once again. Fearsome fighters, masters, and powerhouses come at him one after another. The strong clash with the strong, blazing past each other like the wind. The ultimate unstoppable battle-action story begins now!