This is a special episode of Lovedol. It's also called episode 13 of the series. Lovedol, or Lovely Idol, is a girl group consisting of two generations of idols. The 3rd Generation is about to make its debut, but to their surprise, they have been delayed! The vague reason is only that "they lack something." The manager, and the 3rd Gen. girls too, must find the answer.

Dr. Slump found the secret treasure named “Eye of Rainbow” of legendary Nanaba Castle in the mountain. This treasure makes every dream come true. When the robbery gang of Arale, Ga-chan tried to steal this treasure, Bisna who is the descendant of Nanaba Kingdom took the treasure. Bisna wanted to revive the devil and Nanaba Kingdom. Arale and her friends went towards the secret Nanaba Castle to get back the treasure. (Source: Official Website)

To succeed to his father, Lid Kail sets out a journey to defeat the incarnation of the evil that seems to dominate the world. Longn and Mimau also began to journey to achieve his father’s will. On their way, Key and Bagda join them. They overcome some difficulties, and finally they met Vaii, the evil. They managed to beat Vaii, but it still doesn't solve their problem...

An edited compendium of the four OVAs were spliced together to create a movie which aired in theaters. Included within the was also a prologue, which used 50 extra shots that introduced the world of Dallos before the opening credits.