Since the early childhood Tatsugoro Watanabe devoted his life to education in tailoring. In 1856, he was apprenticed to a tailor in Tokyo at the age of 12. Watanabe finished his apprenticeship in 1868.
In 1868, upon finishing his apprenticeship, Tatsugoro Watanabe returned to his hometown and started teaching sewing to children in the region while practicing as a tailor. Later, starting with Chonan Primary School, he taught tailoring at Chiba Normal School for Women, Tokyo Women's Normal School, and others, and was subsequently appointed Ministry of Education official.
From 1881 Tatsugoro Watanabe started to establish private schools such as Wayo Saiho Denshujo (later Tokyo Kasei University), Kyoritsu Women's Vocational School (later Kyoritsu Women's Educational Institution), which pioneered vocational training for women in Japan.
He also wrote textbooks on sewing techniques and training, and spread a new technique of sewing called the Watanabe Method.