If this is supposed to be a secret it must be Vegas' worst kept secret with 1900+ reviews. Officially this pizza shop doesn't have a name...
Many a Yelper have just accidentally stumbled onto this pizza place in the Cosmopolitian en route to something else. Unlike them, I cheated, using Yelp and the Internet to do the dirty work for me. It also helps that I saw other people just randomly going into the 3rd floor with whole pizza boxes. Once you hit the 3rd floor, look between Jaleo (the Spanish place) and Blue Ribbon (sushi) for a small hallway filled with records.
The pizza place is supposed to be small and simple; No1DP notes that it's reminiscent of the pizza joints he used to frequent back in NY/NJ. There's seating and counter space only for ~5 people and there's only 2 pinball games. The concept's really simple: pick pizza for slice or customize a whole pie.
No1DP was craving pizza as Japan really doesn't know how to do a good pizza. I was there for another reason: to try the concoction known as "white pie".
Crust: Thin and crunchy, which the No1DP says is the way to do a New York-style pizza. The pizza gets cold quickly so eat it while you can. No1DP says that this is why you see people eat this pizza fast - there's not much crust to absorb the heat.
-Veggie Supreme: Came to ~$8.00/slice as he had lots of toppings. He says that this is the best pizza he's had in a while and can easily put this in the top 10 pizza joints he's visited.
-White Pie ($5.50): The No1DP said to me that each pizza joint does their white pie differently, but in essence this is a cheese pizza with NO tomato sauce. When fresh off the oven the cheese is stringy but it held together well. I really liked the garlic and they are generous with the ricotta - this soft cheese literally just melts in your mouth!
Definitely a must for late night eating, especially if you've been clubbing all day!