Nagayoshi of the period is known through an with a two-character signature, designated at the 17th session in 1968. The published sources open by separating him from his namesakes: there are smiths called Nagayoshi in many provinces, and within one in the Chogi group as well, whom the record as the son of Nagashige, of the Shitoku era. This points elsewhere: 「この長吉は一見して、鎌倉中期から末期にかけての長船長光一門の作と鑑せられ、一門の特色が、刃文にも帽子にも見られる」 (at a glance this Nagayoshi is judged the work of the Nagamitsu group of the mid to late period, and the group's features appear in both the temper and the ).
The is with an , a high and a , with a blade of 74.0 cm. Its is with a flowing tendency and standing grain, with . The temper is a mixed with and , with and entering well and some . The runs in with a tip. The tang has a , file marks and four peg holes, one of them a , with the signature above the holes along the back.
No entry in the old corresponds to this smith. The published sources call him 「いわゆる銘鑑漏であるが、恐らく長光の代表者の一人と思われ、作刀が極めて少いところから、そうなったものであろうか」 (a so-called omission from the directories, probably one of the representative smiths of Nagamitsu's circle, the omission perhaps arising because his extant works are extremely few). They value the accordingly: 「銘鑑の欠を補う好資料でもある」 (it is also good material for filling a gap in the directories).