Kerokero Keroppi no Bokura no Ohimesama / けろけろけろっぴのぼくらのお姫さま

Keroleen gets teleported to a fantasy land through a magical pond. There is a handsome prince who charms her. He wants her to visit more but the boys discover that his kingdom is not a righteous one. The gang has to go save Keroleen and the fate of their town from the false prince....