Sengoku

Sengoku (センゴク) is a manga series by Hideki Miyashita. It was serialized in Young Magazine.

Plot
Mounted warriors line up and rush to the assault. Brandishing swords on horseback, the warriors slash at each other... This kind of image of feudal combat is all a lie. Well, then, how did Samurai really fight? A declaration of war has now been made against the lie of combat that was forged during the Edo period, and continued uncontested to this very day.