I was about to say something easy to adapt that kid me loved, like Space Cases, Sailor Moon (which exists, I know), or Scooby Doo.
But then I remembered preteen me had an Are You Being Served phase, and I think a TTRPG about a 1970s London department store would be infinitely funnier.
Okay. You have unfortunately been hit with the curse that makes you adapt a work you liked as a kid into a ttrpg.
What thing are you adapting?