In Hell, Tobe has been tortured for 300 years now, and his spirit to be free doesn't show any signs of fading. So Tobe is given a final chance to make up for all his sins he committed while alive on Earth, he must use the legendary sword Togari to defeat and destroy a 108 Sins in 108 days. Now Tobe is sent to modern day Japan, where things aren't exactly like he remembered, and defeat the 108 Sins in time, so he can be free again.

This is the story of a wuss named Sakurai Mikito who one day swallows the creation of a creature called Zakuro and becomes an "oni", a superhuman creature with a taste for human flesh. As Mikito is horrified by this change in his once-gentle nature, he decides to leave on a journey with an oni-hunter in order to discover a way to turn back to normal.

The only chance Tobei has to escape from the grips of Hell once and for all is to continue his quest to slay manifestations of human evil. His deal gave him 108 days to achieve his goal. This is Tobei's final day.