What kind of fish does Japanese cuisine usually use instead of tuna?

Japanese food generally uses bonito instead of tuna.

Common bonito, Euthynnus affinis, also known as white tuna and smoked fish.

Bonito is widely distributed in warm waters from the Indian Ocean to the Pacific Ocean. Its typical feature is the pattern on the back near the tail end. Its taste is similar to that of tuna diaphragm, and its fat content is slightly higher than that of bonito. It is widely cultivated in Japan.