With his shimmering scales, the Rainbow Fish is the most beautiful fish in the entire ocean. But he is also vain and proud, which alienates the other fish. As a result, he becomes increasingly lonely. When he eventually loses one of his beloved glittering scales, it is none other than the Little Blue fish who accompanies him on the search into the deepest parts of the ocean. An adventurous journey begins – and the Rainbow Fish learns that together we are much braver than alone, and that true friendship is more precious than the most magnificent coat of scales.