I'll give you a question, please answer with step-by-step reasoning process.
Satsuma Province (薩摩 国, Satsuma-no Kuni) was an old province of Japan that is now the western half of Kagoshima Prefecture on the island of Kyūshū. Its abbreviation is Sasshū (薩州).\n\nAnswer this question: the satsuma is named after a province in which country?

Japan
To answer the above question, the relevant sentence is: Satsuma Province (薩摩 国, Satsuma-no Kuni) was an old province of Japan that is now the western half of Kagoshima Prefecture on the island of Kyūshū.

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So, the answer is Japan