- Born: 1815
- Died: 1870/7/6
- Other Names: 近造 (Kinzou, birth name), 正行 (Masayuki, early smith name)
- Japanese: 細川忠義 (Hosokawa Tadayoshi)
He was born in Edo in 1815, the second son of Hosokawa Masayoshi, second head of the Suishinshi school of swordsmithing, and was raised by his uncle Masahira, in the town of Kanuma-juku (in Shimousa province, today Tochigi prefecture). Trained by his uncle, he began producing his own swords, inscribing his name as "Masayuki."
In 1835, at the age of 21, he moved to Edo, where he trained under his father for a time. In 1840, when Masayuki was 26, he and his father entered the service of Tsuyama han as swordsmiths, and were granted the ranking of koyakunin and stipends of 3-nin fuchi.
According to the Kashima-yama Shôzen-ji yuraiki, the history of swordsmithing in Sakura domain began under the Chiba clan, when Kashima Mototane, around the same time that he built Kashima castle, erected a smithy just to the east of it. This smithing workshop was called kaji saku (鍛冶瑳玖). In the Bakumatsu period, as many as ten swordsmiths were working at the site. At that time, most swordsmiths associated with Sakura belonged to the Suishinshi school of swordsmithing, though the Tegarayama school was quite prominent in he region as well. Tadayoshi became the top disciple of Suishinshi Masahide, the founder of the school.
At age 35, in 1849, Tadayoshi was invited to Sakura han by daimyô Hotta Masayoshi, and given a stipend of 15 bales of rice and 2-nin fuchi, and the rank of kaisho bussho. There, he produced numerous famous swords, of which a number survive today.
He died on 1870/7/6, and is buried at Daishô-in in Sakura City alongside his son Hosokawa Yoshinori, who followed in his footsteps as a swordsmith, producing swords at Sakura's kachi saku, and who died on 23 December 1919 at the age of 72.
Tadayoshi's grandfather was Hosokawa Masayoshi (正義), a swordsmith in the service of Utsunomiya han. His uncle Masahira (正平), along with Masahira's son Yoshinori (義規) and grandson Masanori (正規) also served Utsunomiya domain.
Tadayoshi's father Masayoshi (正義) was the second head of the family, and was succeeded in that role, and as swordsmith to Tsuyama han, by Tadayoshi's brother Masamori (正守). Tadayoshi's other brother Masanaga (正長) was a swordsmith in service to Mutsuura han in Musashi province. Meanwhile, Tadayoshi's father's disciple Fujieda Hideyoshi served Kawagoe han, and later Sakura han; Fujieda's disciple Kunitomo Chûsho also served Sakura han, mainly in the production of firearms (teppô).
Tadayoshi himself had two sons. Yoshinori (義則), as mentioned above, was a swordsmith in service to Sakura han, and is buried along with his father. Tadamasa (忠正) also served Sakura han, but worked for a time in Hyûga province as well.
- Signs on-site at Daishô-in, Sakura, Chiba.