Sendai is the capital city of Miyagi Prefecture and the largest city in the TÅhoku region. As of 1 August 2023, the city had a population of 1,09âŠSendai is the capital city of Miyagi Prefecture and the largest city in the TÅhoku region. As of 1 August 2023, the city had a population of 1,098,335 in 539,698 households, making it the twelfth most populated city in Japan.