Surprised no one's posted this yet. This is from Durarara X2 Shou, it's a special referred to as episode 4.5.
Anyways it's an episode filled with flashbacks of some of the characters and when Dota-chin is explaining how he met his crew; Erika and Walker go full otaku mode with some in reference of some popular shows.
The TG happens during this sequence, although not too much process still pretty good.
Link:
https://www.dropbox.com/s/v2ujfd3nlh...%20TG.mp4?dl=0