This fine blade is by Tadayoshi I of Hizen Province. Born Hashimoto Shinzaemon in Saga in 1574, he became a retained sword smith of the ruling Nabeshima clan of Hizen Province. In 1596 he was sent to Kyoto where he studied under Umetada Myoju for three years. Returning to Hizen he set up forge in the castle town of Nagase, to establish a school which was to last for beyond the Edo period. In 1624 he was invested with the title of Musashi daijo, and assumed the name Tadahiro, which he used until his death at the age of 61 in 1632.
Hizen School swords are characterized by the finest konie hada with rich and even jinie. The hamon of rich ko-nie varies from suguha, to gunome, and a characteristic form of rounded choji with long ashi sometimes reaching down close to the cutting edge. The work of the first generation in particular often has pronounced chikei and sumihada, with fine variations in the hamon.