Yes, indeed A.S. Fortuna is packed with Japanese restaurants from each side, its amazing.
Kagura, is indeed nice and the only flaw that I found in this place is the Sukiyaki, the tofus in it were a bit humongus, a bit unproportioned. But the taste was still good as it were in any place.
Ha-Nya in Asia Hotel is also good, thats where I always go when I have late night cravings, because it's a 24hr one.
Earlier this afternoon me and my friend wanted to go to a japanese place and have tea, our choice was Chibori, the one in IT-park. It was a bit expenssive from the rest, but the salmon and tuna sushi just melted in your mouth, the seafood was indeed first class. Now about the tea, it was very fine as well, theres no other good tea compared to the one that you have under a rainy weather, no matter where or how expenssive you got it, hehehehe. Though they open on 11:30am, then closes around 2pm, then opens up again at 5:30pm until late, daily, I guess.