The Mafū-Ba (亀仙人最後の魔封波！！ Kame-Sen’nin Saigo no Mafūba!!, lit. "The Turtle Hermit’s Final Demon Sealing Wave!!") is the one hundred forty-sixth chapter of the Dragon Ball manga. This chapter's anime counterpart is the middle portion of the episode "Roshi's Gambit".
King Piccolo tells Master Roshi that he is foolish for challenging him. Roshi tells him that they have met before, and reveals that his master was Master Mutaito. Piccolo is shocked by this revelation, and Roshi decapsulizes his Electric Rice Cooker. Tien realizes what Roshi is planning to do. On board the airship, Emperor Pilaf, Shu, and Mai are confused, but Piano seems to understand the threat.
Roshi then attempts to use the Mafūba. Piccolo is quickly trapped within the technique, and Roshi seems to have everything under control. However, he misses in his attempt to seal Piccolo inside the rice cooker, the final part of the technique. Piccolo is released, and Roshi tells him that someday he will be defeated. Having finished the technique, Roshi dies. At that moment, Goku (who is riding with Yajirobe to Korin Tower) gets a strange feeling that something bad has happened, which Yajirobe brushes off.
After briefly exulting in his victory, Piccolo telekinetically brings up Roshi's five Dragon Balls from the ground, then regurgitates his two. He happily claims that his youth will now be restored, as Tien watches helplessly.