Yukka first appeared in the chapter where he was looking for his Spinda after she ran off. Torchic and her friends helped Yukka look for his Spinda. They went in a forest and started there first. Mightyena found a swarm of Spinda. There were too many of them and Yukka held out a photograph so the group can compare which one was his.
Clefairy found a Spinda sneaking in some bushes and Yukka recognized it as his Spinda. Yukka at first was reluctant to get Spinda back but Torchic's word made Yukka want to get Spinda back. Yukka apologized to his Pokémon and explained to the group the cause behind Spinda running away from her.
Spinda is Yukka's only known Pokémon. She ran off after Yukka gave her a nickname that she didn't want to be called.