Mashin Eiyuuden Wataru

Wataru Ikusabe was just a normal fourth grader - until he was somehow transported into another world and dubbed its savior. In this world, the evil King Doakudar has taken over Mt Soukai and caused the rainbow in the sky to turn white, and it's up to Wataru to defeat him and return the colors to the rainbow. With the help of the young Shinobu clan leader Himiko, gruff Shibaraku and the feathered spy Kuruma, Wataru will climb the mountain and bring down the forces of evil with his mecha Ryujinmaru!