Etymology and distribution of 胆.

Tan 【胆】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Aichi-ken , Shizuoka-ken . Originated from Nagano-ken Nagano-shi Shinshin-cho machi near Koshido (old: Natsume). A place name with a record in the Azuchi Momoyama period. Tell Fukui-ken that it was also called "summer plum". Estimated in the Edo period. 夏梅 Natsuume reference.