Finding a good, authentic Japanese restaurant which offers high quality fish is not easy, but Fukurou is definitely one of the best ones I've tried so far.
With good quality comes high prices, obviously, but they offer fix price lunch menus which are an excellent way of tasting many different things at an affordable price.
All the fixed menus come with pickled vegetables, a potato(ish) salad, miso soup, coffee and water.
I ordered "Jubaku Kaisen" with raw gamberi rossi, salmon, tuna, scallops, on a bed of steamed rice, which was served with the extras I mentioned above, and it all cost €20. I highly recommend the Jubaku Kaisen to anyone who loves gamberi rossi, it was truly excellent.