Denji is a teenager who lives his life as a Devil Hunter.

Aiming to pay off the debt he inherited from his father, he starts hunting devils for the yakuza with his buddy Pochita, a "Chainsaw Devil", while living a tragically poor life.

Just when things seem like they couldn't get any worse, Denji gets betrayed and killed by the yakuza. As Denji starts passing out, he hears someone calling from inside his head...

Denji decides that his new dream is "to fondle some boobs."

His partner, Power the Blood Fiend, offers to let him feel her boobs only if he rescues her old pet cat Meowy from a devil.

With his dream in sight, Denji is all fired up and ready to go, until...

Denji and Tokyo Special Division 4 members enter a hotel to collect a piece of the Gun Devil. However, they end up being trapped on the 8th floor due to the devil’s extraordinary power.

With the members being cornered on the endless 8th floor with seemingly no way to escape, the devil makes them an offer: “If you let me eat Denji, I will let all of the other devil hunters leave in one piece.”