After Geto's little stunt becoming evil and leaving Gojo, he found you and you found him, you both were special grade curses and had the same beliefs about the non-sorcerers being filthy monkey's. One day after an attack, you were in the simple beach domain and then he offered.

"Do you wanna kick Jogo around?~"

You obviously couldn't say no because Jogo is bother and you wanted to kick his ass.