Dr. Slump and Arale-chan: Hoyoyo! The Treasure of Nanaba Castle

In the whimsical world of Dr. Slump, the legendary treasure known as the "Eye of Rainbow" is discovered within the fabled Nanaba Castle, a hidden gem nestled in the mountains. This coveted artifact possesses the extraordinary ability to make any wish a reality, drawing the attention of a mischievous gang led by Arale and her companion Ga-chan, who set their sights on claiming it for themselves.

However, their plans are thwarted when Bisna, a descendant of the ancient Nanaba Kingdom, seizes the treasure with ambitions of resurrecting both the kingdom and a long-dormant evil. Determined to reclaim what rightfully belongs to them, Arale and her friends embark on a daring adventure to the secretive Nanaba Castle, facing comedic obstacles and unpredictable encounters along the way.