1981 Graduation of high school,
1983 Finishing Computer school and Commercial-Bookkeeping school,
Employment at his father, Daisuke Hamaguchi as apprentice,

When he was born, his family was all of smithery. He, young Sei was always enjoying a hammer at his father's working place in TOYOKUNI factory.
While his student days for 6 yeras, he always helped and tried his father's smith work,
and he therefore could learn and study naturally in his every day's experience of seeing, watching, trying about Smith-Work.

After his guraduation of school, he consentrated really his smith-work under teaching
by expert of Smith-work, Torakiti and Daisuke Hamaguchi.
It is now, he can produce every model's of Forging knives, including agriculture-forestry knives, Cooking knives etc.,

He is getting recently about "Tosa Special Forging Techinics" newly for making Outdoor knives, and also studying design, function, processing technics for his knives.