Look, I've played this level over and over again and have seen no sign of Jirachi. Because I do not know exactly where it appears, I have to kill every freaking Pokemon(which takes awhile), and I still come up empty handed. Please help! Yes, I have more than 40 customers in my shop.
I'd suggest not killing everything. When I try to collect the streetpass legendaries, I use my Speedy+ Crobat and run through the level until I see one of them. Then I switch to a Gutsy+ Pokemon and hope for the best.