Just answer me, what event this Arabic guy attended?

Hints-

This guy's outfit might be regarded as one of the cosplayers, and he became quite fame after attened #87.

Some said this is a big site to visit. Several anime have references about it.

Or simply just say it's a miracle of the Doujin(Fan-made) community. Also (sort of) the cradle of Touhou.

Hold twice a year.