The following characters appeared in the episode "Minding Motsuki":
Luna Girl arrives at PJ Masks HQ and asks Gekko, knowing that he's handled babysitting before, for help when Motsuki refuses to do what she says. Gekko shows Luna Girl that Motsuki's not a baby, and she shouldn't be treated as one.
Do not treat others like a baby.
This is the second time one of the PJ Masks is alone in their HQ.