According to recent studies, the Mihara school was founded by Kokubunji Sukekuni 国分寺助国 in Bingo province 備後国 (Hiroshima prefecture) around the Shochu era (1324-1326), at the end of the Kamakura era.
But two of the most famous blacksmiths in this school are Uemon-no-jo Masaie 右衛門尉三原正家 and his son Masahiro 正広. Masaie has long been recognized, and still is, as the founder.
In the history of this school of Yamato Den tradition, three great periods are distinguished, from the youngest to the latest, called ‘Ko-Mihara’ (1324-1394), ‘Chu-Mihara’ (1394-1429), and ‘Sue-Mihara’ (from 1429).

This forge was located at the Buddhist temple Kokubun-Ji of Bingo 備後國分寺, in eastern Hiroshima prefecture. Kokubun-Ji are temples that were created in the Nara era (710-794). They were built in every province of Japan. Many have now disappeared or are in ruins.
It was common at that time for blacksmiths to work in the temples, which were then the regional central power and provided them with some security.

This school forged in the tradition of Yamato-Den, with straight quenching lines (Suguha), and a elongated Kissaki. Their style has always been very sober and conservative. This school may even be older because a publication of an article in the Meikan talks about a generation of Masaie towards the Tenpyo era (729-749). Mihara Masaie would thus be at the origin of the rebirth of this lost tradition.
Another technical point would confirm the forging of blade since ancient times, the high quality of ferrous sand from this region that would have been exploited long before.

For the productions of the Sue Mihara period, from 1429 onwards, the blades of this school were less curved than before, but they remained among the most gracious of the productions of other schools of that period.
This is what we find in this blade presented here, with a beautiful grain, an utsuri, a straight hardening line and a slender and fine shape.