Among the familiar faces at Kenji Machida’s Yamayo booth at the International Boston Seafood Show last week were exporters, distributors, and fishermen from New Bedford, Gloucester, Portsmouth, and New Brunswick. They are Machida’s friends from the days when he worked in an office in Wakefield exporting their lobster, snow crabs, herring, tuna, and monkfish to Japan. Machida had returned to Japan to export seafood to the U.S. But the giant earthquake and resulting tsunami nearly wiped out his business in Hachinohe, 200 miles north of the quake’s epicenter. Because of efforts to get his $50 million a year firm up and running, the company