Based on a recommendation from 'cl', a fantastic group of chowhounds got together to try out Gaja. Their specialty is the okonomi-yaki dish which is basically a battered mix of different ingredients that get cooked on a teppan in front of you.
Gaja's menu is huge. Suffice to say that they have a few categories of food and then a gazillion variations on it. What our group ended up choosing was:
Pork and kimchee
Modan Mix, or whatever #2 was on the top ten list (no kidding they had an Okonomiyaki Top Ten list)
One other, but can't remember what it was
Spicy cod roe & mochi & cheese
Parfaits and ice cream
Luckily one of the group had some experience with okonomi-yaki before and cooked up the first one, spread the okonomi-yaki brown sauce on top and sprinkled large bonito flakes and nori on top. It was served on the side with a ton of condiments that included kewpie mayonnaise (definitely worth adding), though a lot of the group did without.
The table to our left included one of our group's colleagues and they were lovely and informative about Gaja. They mentioned Gaja as one of two places that they knew of that served okonomi-yaki and the other was smaller scale so they preferred Gaja.
Most everyone enjoyed the Mix, and a portion of the group really enjoyed the roe-mochi-cheese monja-yaki. I'd recommend if you go, to bring at least three to four people, order one of those fantastic looking tofu salads and go to town. That's basically what the table to our right did. And it might be worth finding out what the difference would be with a Hiroshima style okonomi-yaki might be like.
Each one ran between 10 to 15 tops. So I think the split between each of us was a little over 20, which included cocktails, beers and drinks, desserts. Pretty decent and very communal eating.