Osaka was the capital at some point. The capital of Japan moved quite a few times a few decades at a time: Naniwa, Asuka, Sakurai (Nara), Osaka, Fujiwara-kyo, Heian-kyo… Heian-kyo was the capital the longest by a long shot, and was renamed Kyoto at some point early on - like the previous person said, literally capital city. Osaka was capital for a bit some time in the mid 600s, not long at all, but that’s also the period where Japan got real big and important.
Osaka was the capital at some point. The capital of Japan moved quite a few times a few decades at a time: Naniwa, Asuka, Sakurai (Nara), Osaka, Fujiwara-kyo, Heian-kyo… Heian-kyo was the capital the longest by a long shot, and was renamed Kyoto at some point early on - like the previous person said, literally capital city. Osaka was capital for a bit some time in the mid 600s, not long at all, but that’s also the period where Japan got real big and important.