Hang In There, Kakarot! You Are No. 1! (頑張れカカロット！お前がＮｏ．１だ！！ Ganbare Kakarotto! Omae ga Nanbā Wan da!!) is the one hundred fifty-ninth episode of Dragon Ball Z Kai. Its Japanese air date is May 10, 2015.
Goku and Kid Buu continue to fight, each taking powerful blows from each other. Kid Buu folds himself into a ball again, and hits Goku hard. Goku puts all of his energy into a massive Kamehameha, but Buu just reforms afterward. Goku returns to his normal state, collapsing from exhaustion. Vegeta then steps in, but that finds he is no match for Buu. Buu cleans his clock, and just as he's about to deal Vegeta the finishing blow, Goku pushes him out of the way. He then powers back up to Super Saiyan 3 and continues their furious fight. Vegeta reminisces about all of the fights he and Goku were in. He finally admits to himself that Goku is stronger.