Kanayama Tsukutomi was an active blacksmith who not only designed and sold his own blades through the traditional wholesale market, but according to his son, he also helped to fill other orders for different blade makers including Chiyozuru Korehide. Tsukutomi's son Tetsuo-san explained on 2 separate occasions to me that his father worked and was known as a "shadow blacksmith" in his capacity of making some of the blades for Chiyozuru. I have no evidence.
His son Kanayama Tetsuo, shown was born in 1950 and he has continued the craft and traditions of his father and at this time has gained a reputation for his fine small kiridashi kogatana knives and large survival type knives.One of Kanayama Tetsuo blacksmithing trademarks that he is known for is hisinventive and artistic use of kamaji and watestsu.
Kanayama Tsukutomi was a blacksmith from Tokyo and the
blade pictured below was made by him in the 1940's or 1950's. It is known that his original workshop was in Tokyo and he excelled in his field until his death in 1960.
Following are some of the beautiful blades from the Kanayama shop, some are made by the current Kanayama Tetsuro, and some were made by his father Tsukutomi-san.
Kabutowari, circa 1950 is marked down the center KABUTOWARI (reference to weapon*), and to the left MINAMOTO (nom de plume) and TSUKUTOMI-ZO (made by Tsukutomi) and to the upper right is the makers logo.
* Kabutowari is defined as Kabuto as a samuri helmet and Wari to split. The weapon of kabutowari is a close quarters weapon uesd by ninji or other warriors. Two web pages to follow regarding Kabutowari.