Dragon Ball: Daimaou Fukkatsu

The story is set right after The 22nd Tenkaichi Boudouki and everyone finding Kurirun dead, along with a note with the Demon symbol on it. Master Roshi explains that Piccolo Daimaou, an ancient evil being, has somehow come back and Goku rushes off to stop him and revive his dead friend, Kurirun.