Unbearaboy!

is a Rank S Fire-attribute Merican Yo-kai of the Charming tribe.

The Yo-kai Medallium bio reads; "Unbelievabou entered his rebellious phase and became an incredibly mean little brat. He keeps a lot of rubber bands in his pants pockets."

Bad Boya evolves from Unbelievabou when fused with a Bad Ball.

Angie
In Yo-kai Watch 3 Tempura, Bad Boya is Angie's childhood friend. Even as Angie grew up and couldn't see Yo-kai anymore, he still watched over her.