Outlaw Star follows the outlaw Gene Starwind and his eleven year-old business associate, Jim Hawking. Together they run a small jack-of-all-trades business on the backwater planet Sentinel III. After the two take a job as bodyguards for a mysterious outlaw, they find themselves the owners of the XGP15A-II, a highly advanced prototype spacecraft, and the caretakers of a bio-android named Melfina, The series follows the exploits of the slowly growing ragtag crew.

Mugen is a ferocious, animalistic warrior with a fighting style inspired by break-dancing. Jin is a ronin samurai who wanders the countryside alone. They may not be friends, but their paths continually cross. And when ditzy waitress Fuu gets them out of hot water with the local magistrate, they agree to join her search for the “samurai who smells of sunflowers.”