Ushio to Tora

It centers around the travels and battles of one Aotsuki Ushio, who is constantly being stalked and aided by a gigantic, supernatural and sometimes invisible tiger (Some people describe it as akin to Calvin and Hobbes on acid).

Ushio's family maintains a Shinto temple in Japan, where 500 years ago, his samurai ancestor battled that same tiger to a standstill, and eventually trapped him against a rock using, a blessed spear called the "Beast Spear", which in addition to its intrinsic formidability as a weapon, can also boost the physical powers of the user. While cleaning out the temple storage, Ushio accidentally unseals the chamber which Tora was trapped in. Initially, Ushio wisely refused to remove the spear p...