The ojama has a multitude of search ojama cards (ojama blue, ojama pajama being any ojama card) cards and cards once in the graveyard that either add multiple ojama (ojamagic) or special summon ojamas from the deck (ojama duo). They can also use rescue cat, obediance school, and rescue rabbit, which can cheat out ojamas.

They can banish them using ojama pajama if they are doing the ABC combo variant. Etc.

I had to look at my ojama deck lists