After he witnesses his father’s murder at the family dojo, Ryo Hazuki dedicates his life to finding the man responsible — a mission that takes him from the streets of Yokosuka, Japan to the sprawling metropolis of Hong Kong, and beyond. Soon he’ll learn that larger, mystical forces are at play as he trains to become the ultimate martial artist in his quest for revenge.

Middle-aged businessman Ryoma is reincarnated in a magical world by three gods. He's a child again, and he spends his days with his tamed slimes.