Tarumoto 【樽本】5 The Japanese surnames etymology dictionary.
Ooita-ken , Aichi-ken . Originated from Kouchi-ken (formerly Tosa country). A place name with a record since the Asuka period. Ooita-ken Saiki-shi Tsurumi Dai Kai Kaoriura tells that Kouchi-ken is out. There is a tradition with Fukuoka-ken . Estimation from tradition lived in the age of warring States.