Paco Party

Problem solved, thanks.

Yes, I've defeated all of them, so here it is. Thanks in advance, it's driving me crazy.

I'm in route 4, "playing" hide and seek with Nim, and after finding her like 5 or 6 times, she's just gone, can't find her anywhere. The fence is still locked, the aquarium guarded by a blue nurse and I've checked everywhere, is this a bug or am I missing something?