Greetings to all!
I found information about this smith, correct me if I'm wrong. I will also add new photos of the seller. The problem is that there is a metal stratification.
SSESHU JU MASAHIRO
Tsuto School, Osaka district, 1650-1700.
This is Master Massahiro, who lived in the province of Setsu, the eastern part of Japan, opposite the island of Awaji. Masahiro is a student of the school's founder, Sukehiro, who later adopted the name Tsuta.