Lucas Irwin distinguishes himself from the rest of the small crew at NaRa-Ya, a high-end Japanese restaurant that opens next week on the Southwest Waterfront, when he turns his attention away from a countertop where he’s been braiding tangerine-colored strands of raw salmon and lifts his head to say hello. On a recent visit to the kitchen in the third-story space that looks over the Potomac River, the Hawaiian chef wiggled his pinky and thumb to flash a friendly a “hang ten” hand gesture. Irwin, the latest in a string of sushi chefs attached to the long-developing waterfront restaurant, left Maui a long time ago, using experience working for Iron Chef Masaharu Morimoto and Hawai’i legend Alan Wong as a springboard to travel around the country for jobs in places like Beaver Creek, Colorado, the island of Nantucket, and, most recently, Palm Beach, Florida, where he answered a Craigslist ad from NaRa-Ya culinary director Kaz Okochi. The “neo-traditional” Japanese dishes Irwin plans to send out when NaRa-Ya opens for indoor dining on Wednesday, March 10, retain a tropical island vibe with a flood of colorful flowers and fruits like kiwi, passionfruit, and candy kumquats.