“There is no room for carelessness,” says the elderly man who, since he was 15, has dedicated his life to making an indispensable ingredient in Japanese cuisine: katsuo-bushi. The contrast between the modern Japanese food industry (fast, cheap manufacturing) and the traditional katsuo-bushi workshop central to this observational documentary could not be more striking. Not only is the workshop staffed by aging artisans, but time has also scarred the equipment. It’s rusty and it rattles, but it still works. Katsuo-bushi patiently records the time-consuming, complex preparation of a type of fish called bonito: from cutting the fish into a specific shape and trimming the belly to the multi-day smoking process in special machines to drying it in the sun. Director Yu Nakajima captures other links in the katsuo-bushi trade, such as the fish auction and a Michelin-starred restaurant, but he never loses sight of the workshop for very long. In that small, clear-cut world, these senior citizens continue to work with full concentration, but they aren’t ignorant of the economic interests and the fishless seas that make their immediate future insecure.