Kero Kero Chime

Mimori is the princess of the frog kingdom, a fantastical place populated by the human frog tribe and, well... frogs. One day a young boy named Aoi shows up on the borders of the kingdom, claiming that Mimori's elder brother Makaeru cast a spell on him that causes him to transform into a frog when splashed with water. Together, Mimori and Aoi set out on a journey to find a spell to cure him. (And things only get weirder from here on out.)