Long ago, in an era when darkness still roamed the Earth, a mysterious castle rises among the five mountains known as the Devil's Hand, whispered in legends to guard the Sleeping Princess. The castle’s shadowy master, Lucifer, rules from within, a vampire-like figure whose plans hinge on waking the princess with a power that could change the world. The legend promises that whoever frees the Sleeping Princess will earn a coveted place in a powerful master’s training.
Years later, eleven-year-old Goku [Masako Nozawa] arrives at Kame House to seek training with Master Roshi Kohei Miyauchi, drawn by stories of combat mastery and the chance to deepen his skills. Roshi watches an exhibit of training routines while pondering a future student, then the scene broadens as a tiny monk named Krillin Mayumi Tanaka paddles in by rowboat, begging for instruction. Roshi’s stubborn pride clashes with Krillin’s persistence, and Krillin wins his way in only after trading bizarre bribes—magazines that catch Roshi’s eye and curiosity. The two boys soon discover the legend of the Sleeping Princess and the castle that lies to the west, and a new, shared quest begins with a single rule: the one who brings back the Sleeping Princess will become Roshi’s student.
Meanwhile, a blonde, impulsive girl named Launch Mami Koyama stumbles onto the tale and vows to claim the prize for herself. Alongside the two hopeful pupils, Bulma Hiromi Tsuru, Oolong Naoki Tatsuta, Yamcha Toru Furuya, and Puar Naoko Watanabe are on summer vacation adventures of their own, and they converge with Roshi’s crew as they set course toward the fabled fortress. The group boards Bulma’s Capsule jet and soars toward danger, chasing rumors of a princess trapped behind the Devil’s Hand.
Night falls as the jet nears the castle, and peril erupts when ogres strike, bringing the ship down and abducting Bulma. Inside a sunlit bedroom, Bulma encounters Lucifer himself and his eerie butler Igor, who treat her as a guest while guiding her toward the bizarre ogre convention that honors the Sleeping Princess. Lucifer’s true nature surfaces as he binds Bulma with vines, preparing to drain her blood to awaken the princess, a ritual that seethes with menace and dark intent.
Hearing Bulma’s cries, Yamcha Toru Furuya, Oolong Naoki Tatsuta, and Puar Naoko Watanabe mount a rescue, disguising themselves as ogres with the help of Oolong’s shapeshifting and Puar’s transformations. Goku Masako Nozawa and Krillin Mayumi Tanaka simultaneously collide with ogres and the swamp-brute Ghastel Daisuke Gori, facing ordeals that test their resolve as they stumble into the Sleeping Princess’s chamber, where a colossal jewel seems to house the coveted prize. Launch arrives on her motorcycle, seizing the relic and breaking away, while the others’ disguises falter as five minutes pass and Oolong’s illusion fades, revealing their ruse.
As the chase unfolds, Launch’s sudden arrival delivers a twist: she changes into a blue-haired version of herself after a sneeze, the result of a magical curse that briefly flips her mood and allegiance. The combined group – Goku, Krillin, Yamcha, Bulma, Oolong, and Puar – pursues Launch but finds themselves outmatched as Launch bolts away with the Sleeping Princess. In the ensuing chaos, Goku recovers the princess only to confront Lucifer again, who threatens Krillin’s life unless Goku yields. Goku refuses, taking a heavy beating from the ogres and a pink demonic bite that leaves him momentarily paralyzed and bare, Krillin’s distress palpable as his friend fights for breath and hope.
The night crescendos under a full moon’s pale light when Lucifer channels moonlight to power a deadly weapon aimed at destroying the rising sun. Goku and Krillin rally as the others press a desperate defense, and a wounded but defiant Yamcha knocks Igor out of the picture, freeing Bulma from captivity. Goku channels the Kamehameha, shattering the cannon’s energy core and triggering a collapse that dooms Lucifer’s fortress. The castle buckles and falls; the Sleeping Princess vanishes into the dawn, and the Devil’s Hand lies broken, its ominous shadow finally lifted as sunlight pours over the land.
With the danger vanquished, the crew regroups on a bruised but victorious front. Krillin’s remorse for his earlier actions toward his comrade lingers, even as the group poses for a peaceful moment to celebrate survival. They return to Kame House, where Roshi’s pride brightens at the sight of his two would-be pupils, Launch and the two boys, ready to embrace their training under his tutelage. Yet the day ends with a small, comic twist: Launch hardens into her bad self and fires at Roshi and the group, prompting a sneeze that flips her back to good, and she apologizes as the crew steps away from danger, the sun rising and a new chapter in their training about to begin.
