Gumball Watterson, a 19 year old that now its spend his time doing nothing and doing petty crimes likes graffiti, yet nobody takes him seriously really.

After some bad luck, he dropped from college and now he's doing whatever he wants.

As a favor for Nicole, Yuki hires him as a janitor in the Rainbow Factory, under supervision of her daughter Masami, which have a "complicated" relationship with the cat.

He and Darwin aren't as close as they used two, specially since he's still in college and dating Carrie, yet they still love and have each other's back.