Mutenroshi, also known as Master Roshi, is a legendary martial arts master who resides on a secluded island at Kame House. In this film, he is first seen absorbed in watching an exercise program, which immediately establishes his easily distracted and lecherous nature. When Goku arrives seeking training, Roshi is initially unresponsive until Goku shouts to get his attention. Shortly after, Krillin arrives and offers Roshi a stack of magazines as a bribe, which swiftly changes Roshi’s mind about considering the boys as students. Instead of training them directly, Roshi recounts the legend of the Sleeping Princess, a beautiful figure held captive in Devil’s Castle by the vampire-like Count Lucifer. He sets a challenge: whichever boy retrieves the Sleeping Princess will be accepted as his disciple. This test reveals Roshi’s belief that worthiness must be demonstrated through action rather than granted freely. His motivations blend a desire for amusement with a genuine wish to assess the boys’ courage and skill. Later, when Bulma and her friends arrive looking for Goku, Roshi deliberately misleads them, sending them toward the castle as well, further showing his playful and mischievous side.

At the film’s conclusion, after Goku and Krillin return with Launch, Roshi mistakenly believes Launch is the Sleeping Princess and joyfully accepts both boys as his students. This acceptance highlights his pride in their accomplishment and his role as a mentor. However, the moment is undercut when Launch sneezes and transforms into her violent blonde personality, forcing Roshi to flee from her gunfire. This chaotic episode underscores the unpredictable drama that often surrounds him. In terms of abilities, Roshi is the originator of the Kamehameha wave, a powerful energy attack, and a highly skilled martial artist, though he does not engage in combat during this film. His role is that of the eccentric, wise teacher who sets the entire adventure in motion and provides comic relief through his quirky behavior. His relationship with Goku and Krillin begins here as a master-student dynamic, with Roshi exhibiting a mix of paternal guidance, mischief, and a fixation on attractive women. Overall, his character in this story is defined by his playful cunning, his perverse tendencies, his dedication to the martial arts, and his function as the catalyst for the boys’ journey.