Yasuyoshi of Chōshū, the successor generation of the -school smith of that name, is known through three designations: a dated in the Ōei era (13th session, 1965) and two signed (49th session, 2003, and 61st session, 2015). The published sources trace the name to an earlier Yasuyoshi, a son of Ō-, who is said to have moved from to Nagato, and they record that 「その子孫が長州に栄え、これを長州左と称する」 (his descendants flourished in Chōshū, and this line is called Chōshū ). Works signed as Chōshū Yasuyoshi survive with Eiwa and Ōei dates, and of these the sources write that 「応永年紀のものは作柄・銘振りから明らかに代替りの安吉と鑑せられるものである」 (those dated Ōei are, from their workmanship and signature style, clearly to be appraised as the successor Yasuyoshi); whether the Eiwa pieces belong to the late years of the first generation or to the successor is left as a subject for future research.
The dated is the anchor of this generation. It is a blade with and only a slight ; the is that flows into toward the edge, with ; the is a shallow, broad with coarse adhering well and running frequently, and the tends toward and . The tang carries Yasuyoshi on the and the date with the added inscription Chōshū-jū on the . The sources judge that its workmanship carries the character of the line, and add that 「応永年紀のあるものは他に類がなく、資料的にも極めて貴重である」 (no other example with an Ōei date is known, which makes it extremely precious as documentary material).
The 2003 is with a rather large two-character signature cut with a thick chisel, and because its hand is close to the Ōei-dated example it is assigned to the Yasuyoshi active from the end of the period into the Ōei era. It is broad, extended in length and somewhat thin in . The is mixed with and , flowing in places with the grain standing out, with fine thickly applied, , and a slightly blackish steel colour; the is mixed with , well covered in with patches of coarser , , and . Against his usual style the sources find the forging rougher, the temper larger in pattern and the stronger, so that the blade 「些か野趣をおびた作域を見せている」 (shows a range of work with a certain rustic flavour), and its long, deeply returned with uneven adds to the force of the wide, long form.
The 2015 , recorded under the same name without a generation being assigned, is also a large piece in the nine- range. The sources describe the usual Chōshū Yasuyoshi manner as one in which 「作柄は通常、刃沸が弱く匂勝ちの刃文で、刃に近く棒映りを現し、備前気質の混在した感のあるもの」 (the workmanship ordinarily has a -dominant temper with weak , near the edge, and a sense of character mixed in). This blade departs from it, with thick , prominent , a bright and clear , and an that breaks up into strong, flame-like ; a two-character signed blade designated at the 31st session shows the same aspect and is accepted as one mode of his work. The sources see in it a likeness to Ō- and close by calling it 「覇気の漲った一口である」 (a blade filled with vigorous spirit).
No provenance is recorded for these three blades; at designation the was held by the Iijima family of Ibaraki and the 2003 by Katō Nagakazu of Fukushima.