I finally had a chance to try this after walking past the restaurant many times.
You can find this in Hongik and Wangsimni too.
I went to the branch at Hongik University.
1st, you have to order toppoki, they offer 2 types, stir fried or just the usual with sauce + choose the level of spiciness. 2nd, you choose the type of meat you would like to add on. (They offer deep fried squid, mexican wings) I chose the deep fried squid. 3rd, you can add rice balls (optional)
It is SUPER DELICIOUS. The squid was on point, crispy and tender. The toppoki was good and addictive (the sauce I guess!). However I have to warn if you don't take spiciness. I ordered level 1 but my friend and I thought it was a bit tad spicy.. I don't know if you can ask for a non spicy one though. Its around 8000/pax~ DO TRY IT.