Reincarnation insurance is a system that, with the contract taker as recipient, makes use of the Insurance Quanatum to provide a new life after death.

The insurance premium was paid and all the conditions were settled, yet upon awakening in the new world the opening act was a horrible disaster, immediately losing an arm to a wild beast. On top of that, due to cause unknown, communication through words didn't get through. That, together with taking along modern Japan's technology, turned the second life into one full of grim prospects from the very beginning.

In a gloomy dungeon where survival without struggle was impossible, a man who lost his left arm was determined to survive, using present day Japan's technology to its full extent. Namely, the peak of cybernetics, mechanical limbs and cyber karate.