My top recommendation for Japanese tinned food is mackerel in brine.
the chunks are usually large, cut into thick, round slices. The ingredients are simple- just mackerel and salt- but the flavour is rich, juicy, and deeply flavoured. In fact, in Japan, it’s said that sabacan, tinned mackerel becomes even tastier after maturing in the tin for a few years. It’s delicious on its own with Japanese herbs like shiso leaves, ginger, or myoga, and also perfect for quick and easy cooking!