Ikki Tousen: The Vigilance of the Purple Dragon

He had remembered the day when his master had died although, thankfully he didn't die a tragic death. He just died like any other and died without regrets, having taught him everything he needed to know in order prepare himself in the real world...

And that includes trying to survive in a region that is caught in a gang war where delinquents alike are battling each other for dominance and territory in a supernatural war that could possibly be in an attempt at taking part in a theater of a dynasty that dates back from millions of years ago...

Or whatever the Hell that means...

Now, Shiryu, an independent freelancer trying to graduate at school, is now going to make sure that the people are safe with the teachers his master has taught him, arming himself with the weapons and gadgets at his back and call and a martial art fighting style that is barely have any direction and power but nonetheless makes up for in pragmatism and no conventional weaknesses...

And he shall bring Hell against the scums and lowlifes alike in the Kanto Region as he shall show no mercy and deliver with the utmost brutality possible...