Shimajirou to Kirakira Oukoku no Ouji-sama

Synopsis (en anglais)

The story centers on Pearl, the prince of the Glitter Kingdom, who is preparing to become king. After he leaves the kingdom to go to Challenge Island, a situation causes the kingdom to lose its precious glitter. Shimajirou and friends set out with Pearl, who lacks self-confidence, on an adventure to find three keys to save the kingdom. (Source: Anime News Network)