FAIRY TAIL: Happy no Daibouken

A member of Fairy Tail named Happy is transported to a different world where the beings are animals, featuring ears and tails. He is accompanied by a talking heart and flies through this new environment, encountering and assisting various creatures, including a bunny, a fox, and a dog. The nature of this world remains unclear, and the possibility of Happy returning to his guild, including a character named Natsu, is uncertain.