The Awataguchi school
The Nihon Kokugo Daijiten dictionary calls the Awataguchi school the smiths who worked at Awataguchi, in Kyoto, from the late Heian period to the middle of the Kamakura, headed by Kuniyori, and singles out “six rotating smiths, Kunitomo and the others”. Tradition attributes the school to Kuniyori, who was not a smith, and to his son Kuniie, its de facto founder; but no certain work by Kuniie survives, nor is there any document of the time that proves the kinship of the six brothers, according to Markus Sesko.
According to tradition, Kunitomo was the eldest son of Kuniie and the first of the brothers, among whom were Hisakuni and Kuniyasu. Sesko places him around the Kenkyū era (1190-1199) and considers him the oldest Awataguchi smith with surviving work, leaving aside a tantō attributed to Kuniyori.
Rotating swordsmith of Go-Toba
The retired emperor Go-Toba summoned him to his system of rotating smiths (御番鍛冶, goban-kaji): he appears in the first list as the smith of the sixth month and, in the list of 24 smiths, of the first. Those lists also include his son Norikuni, his brother Kuniyasu and his nephew Kagekuni, while his brother Hisakuni was the emperor’s forging instructor, according to Sesko.
His name
According to Sesko, he was the eldest of the brothers.
The dates
The Kotō Meizukushi Taizen, first published in 1792, has him die in Kenpō 1 (1213) at the age of 67. Sesko points out that such exact dates of birth and death appear for the first time in that late work and must be taken with caution.