Street Vendors
 

I remember from my younger years that on Sunday, yoyogi park is filled with people selling used stuff. But they were nowhere to be seen when i was there in 2009. I am returning to Japan this year around June, when and where would i be able to find these street vendors?

Also, any recommendation for yatai food? I will be in Sapporo, Tokyo and Osaka, and will not have access to Hakata, but I sure do miss the yatai food....