While no one was looking, Chelsea has turned into a destination for Japanese-food enthusiasts. Exhibit A: Ushiwakamaru from chef Hideo Kuribara, a cult favorite among sushi connoisseurs who decamped from his popular Houston Street spot in 2015. The dining room is simple enough, with less than a dozen or so tables and a lengthy sushi bar. But exquisite fish is what sets this place apart. A reasonable sushi and sashimi combination might include silken amberjack with the richness of oceanic foie gras, tuna that tastes like rare steak, and sweet shrimp more luxurious than lobster, each bite more memorable than the last.