Sushisho Masa is an intimate seven-seater in the basement of a nondescript building in Nishi-Azabu. There's a sense of purpose here, and nothing feels extraneous or out of place (ceramics, in fact, are hidden on shelves covered with paper screens). Fish is prepped and served in tidy wooden boxes on a beautifully simple cypress counter where chef Masakatsu Oka plies his trade.