Jager is a feared bounty hunter, collaborating with GUN to ensure the safety of the world. One day a most intriguing request from the army comes in: to capture a boy with the alleged ability to time-travel, which he's been using highly irresponsibly to hang out about two hundred years in the past. A joke of a case by a joke of a person Jager can easily retrieve to be brought to justice, for sure. Except maybe not, when said boy turns out to possess some terrifying powers, a fuse as short as can be, and also no desire to leave the past behind.