On this page
The Sa school
According to the 往昔抄 (Ōjakushō), as summarised by the Japanese Wikipedia, the Chikuzen school runs from 良西 (Ryōsai), in the middle of the Kamakura period, to 西蓮 (Sairen), 実阿 (Jitsua), Sa, called Ō-Sa, and Sa Yasuyoshi. Ō-Sa signs with a single character, 左 (Sa), and is counted among the ten pupils of Masamune; his only signed long blade is the tachi 江雪左文字 (Kōsetsu Samonji), a National Treasure.
The NBTHK Sword Journal (no. 734, March 2018) gives Ō-Sa tantō dated 1338, 1339 and 1340, and places between 1340 and 1350 the school’s move to the full Sōshū style. It also records the tradition that “Sa” abbreviates Saemon Saburō.
Sadayoshi is one of the 末左 (Sue-Sa), the swordsmiths of the school of the following generation.
Whose son?
- One version makes him the son of Ō-Sa and gives him a work dated in the first year of 文和 (Bunna), 1352.
- Another makes him the son of Yasuyoshi and dates his Jūyō blade to around the Bunna era (1352–1356).
Tradition does not resolve the discrepancy, and neither of the two versions cites its source.
In the lists
A ranking of kotō quality of unidentified origin places among the 上々作 (jōjō-saku), in the Shōhei era and in Chikuzen, a 筑州貞吉 (Chikushū Sadayoshi) and a 左吉貞 (Sa Yoshisada). The first may be him, but the list does not say so.
He does not appear in the Kyōhō meibutsuchō nor in the wazamono lists. In the lists of the NBTHK monthly exhibitions from 1998 to 2024 compiled by Markus Sesko he does not figure under the Sa school; there is only a Sadayoshi of Hōshō, with one blade.