Given the task definition and input, reply with output. In this task, you will be shown an extract from a movie plot and a question. You need to provide the correct answer for it. Short answers containing words that are present in the passage are preferred.

[Based on] The King Piccolo Saga [Dragonball], also known as the Piccolo Daimaoh Saga (Demon Lord Piccolo Saga) is the penultimate saga from the anime Dragon Ball. It occurs after the Tien Shinhan Saga and precedes the Piccolo Junior Saga. It includes the battles between Goku and King Piccolo's sons, Goku's first encounter with the Samurai warrior, Yajirobe, Goku's quest to find the Holy Water, his final battle with young King Piccolo, and the birth of Piccolo JuniorAppearances also made by Yamcha and Bulma but regretably not Bwar or Oolong, nor even Krillin. Ox King and his Daughter Chi Chi are speculated -capricorntiger86Co-produced by Hong Kong legend Stephen Chow (Kung Fu Hustle), Dragonball Evolution is an agreeable if low-wattage live action adaptation of the iconic manga and anime series Dragon Ball. Director James Wong fuses the series fantasy-based characters and devices with a somewhat lackluster storyline involving average teen Goku (Justin Chatwin), who breaks from his wholesale pining for classmate Chi-Chi (Jamie Chung) to that hes at the center of an intergalactic search for the all-powerful Dragonballs by evil warlord Piccolo (Buffys James Marsters). With the help of master Roshi (Chow Yun-Fat, who backburners his stoic screen image in favor of some God of Gamblers/Once a Thief-level hamminess), Goku develops his fighting skills to take on Piccolo and save the Earth. The films abundance of martial arts should please younger and less discerning viewers, but its hackneyed dialogue and sluggish pace (especially in the fight scenes, which stutter where they should flow) may disappoint longtime fans of the book and television adaptations. The CGI effects, which labor mightily to reproduce the source materials eye-popping look, also fall short, though the cast is game, especially Marsters and Chow. [D-Man2010]James Wong adapts the rich mythos of the Dragonball series that grew from a manga into various popular animated series with this 20th Century Fox production starring Justin Chatwin. The plot revolves around Goku (Chatwin), Earth's greatest champion, who must defend the planet against an invading race of alien warriors hell-bent on dominating the universe. Wong directs from his own script, with Kung Fu Hustle's Stephen Chow producing. Buffy the Vampire Slayer's James Marsters co-stars as the film's villain, Piccolo, with Jamie Chung playing Chi Chi and Emmy Rossum portraying Bulma. Hong Kong legend Chow Yun-Fat rounds out the cast as Master Roshi, Goku's mentor in the film. [D-Man2010], Question: What happens to Goku and King Piccolo's sons?

Answer: They fight each other.