Etymology and distribution of 天助.

Tensuke 【天助】^{レベル2
About 20}  The Japanese surnames etymology dictionary.

Hokkaidou , Toyama-ken , Toukyou-to .

① Originated in Ishikawa-ken north (formerly Noto County). A place name with a record since the Nara period.

② Ainu system . Same source. Hokkaidou Sapporo-shi Iwakuta of cold weather in Nishi-ku renamed Noto Yoshiyoshi from Father to Noto Iwasarou. Estimated in around 1875. 能登屋 Notoya reference.