Collect 210 green stars and 77 stamps (all non-character and world crown stamps), timing starts when you select a character and ends when the last needed stamp hits the stamp collection. I'm pretty sure this is also possible itemless, I might do a run if a route is ever made.

I forgot about the sprixie house, it would be 76 stamps instead.

that's just any%+ with stamps but it seems different enough to qualify