Here are the old names used before Meji restoration.
蝦夷 Ezo (Hokaiddo)
陸奥 Mutsu (Tohoku)
坂東 Bando (Kanto)
甲濃 Kaino (Tokai)
大和 Yamato (Kinki)
山陰陽 Saninyo (Chugoku)
伊予 Iyo (Shikoku)
鎮西 Chinsei (Kyushu)
Tokai and Chugoku region names where made up deriving two major old names into one.
By the way in case you didn't know Taiwan was part of Japan during the certain era in your story.
You owe me two.
