Jaco the Galactic Patrolman

Retired scientist Omori lives alone on a deserted island while continuing his research into time-travel. His quiet life in interrupted when galactic patrolman Jaco crash-lands and decides to move in with him. This agent from space claims to be elite, but sometimes it can a little hard to believe. Can Jaco get along with the old man long enough to save the earth from a dangerous threat?

Its bonus chapter is Dragon Ball Minus.