APink performing at G-Star 2013 Busan Korea Bexco
I think A Pink was the only kpop group at the Bexco Korean Games Expo GStar 2013, which you might recall for the Dota cosplay.
The uploader also has other fancams of the event
You can find more photos of Apink at G star 2013 at All-Apink
They’ve also previously performed at the GSL (Starcraft 2) as well as cheering on the players