Moritsugu is an smith of , his name traditionally derived from Yasutsugu, the founder of the lineage, and carried by several hands from the period down into the . The published sources are careful with the name. The lists more than one smith called Moritsugu even within , and the name passed on afterward, so that surviving works range from blades judged to the end of through dated pieces of the Jōwa, Bunwa and Enbun years in the middle of the . His record falls into two faces, an early powerful and a group of dated late works, chiefly . Of one Enbun piece the commentary says plainly that this is the work of the last bearer of the name, 'the Moritsugu who brought that tradition to its close'.
The hand that runs through both faces is a calm, bright . On the late the temper is -dominant and clear, the drawn tight, gathered along it; one Bunwa the published record calls a textbook of work. On the early the same line is a base into which and are set, entering, fine running, the bright. The judges single out this quality above all. The way a tight, bright is tempered to produce a deep -ai, a salt-like depth in the hardened edge, they call 'superb', and from it 'the high technical level of Moritsugu can be perceived'.
The is the steel at two strengths. On the early two-character it is a mixed with , the grain finely standing, adhering throughout in fine particles, entering, and from the boundary a somewhat faint rising, the most refined in his record. On the dated the forging stands a little more, an that at times flows, mixed with and -like mottling, with a clear over it. The on both is essentially straight, turning back in a , sometimes with , and on the a is carved through into the tang.
Within the dated work the published sources draw the period's central observation. The of this generation, they note, shows little conspicuous and becomes for the most part , and in it 'there are two manners, the traditional and a splendid not seen before'. Most of Moritsugu's work belongs to the first of these. The second appears in two of his blades. His mixes reverse-leaning into a of , and an Important Cultural Property dated the eighth month of Enbun 2 (1357) is recorded outright with a temper. The same year, Enbun 2, is inscribed on an Important Cultural Property of 86.0 cm whose temper is recorded as a mixed with , and a long-signed in a narrow carries an era name the published sources read as Jōwa. His shapes are of their moment. The early is wide and powerful with high , thick and in the Kenmu manner, and the are with a feeling or a faint . One rare piece the sources note as unusual for the smith and the school alike, and several of the carry a or goma-bashi devotional carving in the groove.
His place in the school is the one the judges name. His early belongs to the classic manner of over a fine with a bright , while the dated works bring the long Moritsugu name to its end and show both of the period's manners, the tight traditional and the new . The strongest external anchor is documentary. The published sources find that the manner of cutting the signature on his finest matches exactly the hand of the long held by the Uesugi family, the Important Cultural Property known as the . It differs only in that his , carried through the tang, forced the signature onto the rather than toward the .
He is a rare and quiet name. Fujishiro grades him Jō , and the Tōkō Taikan values his work at 900. He has no National Treasures. His record runs instead through the Important Cultural Property tier, three blades among them, one Special and four , with a single prewar , so that nine designated works stand on record. The Enbun 2 is preserved in the Tokyo National Museum, and a second Important Cultural Property survives with its and a recorded provenance from Uesugi Kenshin; the also descends from the Uesugi family. These are patrimony rather than property. The was certified in the Suzuki collection of . Of the remainder the Special and blades are the pieces that survive in private and recorded hands, and even these come to light only seldom, since extant Moritsugu of this period are few. A signed Moritsugu reaching a collector is an uncommon event, and a document of how the school carried its old down to the close of its line.