Okimasa was born November 13, in Taisho 3 and hailed from Koriyama city in Fukushima Prefecture. He claimed to be a descendant of the koto Echizen Yamamura Masanobu family of swordsmiths. Okimasa had three brothers and a nephew who all became excellent smiths.
His study in swordsmithing began under the master smith Kasama Shigetsugu in 1934, an event precipitated after a bicycle trip he made to Tokyo from Koriyama to see the shinsakuto exhibit. Okimasa later married the daughter of Shigetsugu and became his son-in-law.
By Showa 14, Okimasa had opened his own kaji at his residence in Setagaya-machi, Setagaya-ku, Tokyo. During this period he also made swords at the estate of Toyama Mitsuru in Tokiwamatsu, Setagaya. He was a member of of the Nihon Toto Tanren Tosho Gyou Kumiai the Rikugun Gunto Gijutsu Shiyo Rei Kai, and a meisosho, or master craftsman, member of the Koku Koin Kai, which was a national association of craftsman.
Okimasa was held in extremely high regard during his active period. In 1943 the Nihon Token Tanrenji (NTT) and the Nihon Token Shinbunshi (NTS) rated the various modern swordsmiths. They broke the smiths into three partitions, one for the older senior smiths who received honorary rankings, and then two partitions, East Block and West Block for the others, with the East Block rankings considered to be superior to West Block.
The format follows Sumo rankings, and the senior smith at Yokuzuna rank (highest) of the East block was Tsukamoto Okimasa, indicating that he stood without parallel. For more on this click here for Rich Stein’s Gendai Swordsmith listing.
Okimasa was also shinsa-in, or judge, at the later annual Shinsaku Nihonto Tenrankai. He had won all of the major awards, including the Presidents Award at the Rikugun Gunto Gijutsu Shiyo Rei Kai, the Navy Ministers award, the Prime Ministers award, and the Education Ministers award. In the NBTHK’s annual contests, he won the Yusho, or Excellence award once and the top award of Tokusho, four times.
He left many superior works done in the Bizen and Soden styles, and made a sword for the Grand Shrine at Ise in Showa 28. His work also embraces the style of the famous shinshinto smith Kiyomaro, with gunome-midareba and profuse hataraki.
He also produced many works in choji-midare, similar to those of his teacher and was also skilled at horimono. In particular he made a special effort to study and perfect an Awataguchi style ji-hada, and as a result, his ji-hada is especially refined.
Due to the destitute condition most swordmakers lived in after the war, it is said that he made many excellent gimei of Kiyomaro, Ichimonji, and other famous swordsmiths in order to make a living. He enjoyed drinking and it is said that this contributed to his untimely death due to tuberculosis on May 27 in Showa 35 at the age of 46. Some sources indicate he passed away in Showa 33, however, it is known that he entered a blade in both the Showa 33 and Showa 35 NBTHK contests, so it would seem that the Showa 35 date is correct.