Moritoshi is one of the representative swordsmiths of Ko-Aoe, ranked alongside Sadatsugu, Tsunetsugu, and Kōji among the foremost figures of the school. The Aoe group flourished in Bitchū Province, a region long known as a source of iron, forging blades in the areas of Koi and Manju along the lower reaches of the Takahashi River. Those smiths active from the end of the Heian period through roughly the mid-Kamakura period are designated Ko-Aoe. Sword reference works place Moritoshi's activity around the Gen'nin era (1224–1225) in the early Kamakura period. A separate smith signing "Minamoto Moritoshi" belonged to the Kongō Hyōe group of Chikuzen Province in the Muromachi period and should not be confused with the Bitchū smith.

Moritoshi's forging is characteristically of itame-hada mixed with mokume, tending toward hada-dachi — a standing grain that produces what the NBTHK describes as a chirimen-hada (crepe-like) texture. Many works show areas of jifu, and the jihada often takes on a dark, blackish tone with faint utsuri or irregular jifu-utsuri standing out in the darker bands. Fine ji-nie adheres densely, with chikei entering frequently. His hamon is grounded in suguha, with linked ko-chōji, ko-gunome, and ko-midare intermixed in quiet, archaic compositions; ashi and yō enter well, ko-nie adheres deeply, and kinsuji and sunagashi appear throughout. The bōshi is typically straight, turning back in ko-maru, sometimes with slight hakikake. His tang practices distinguish Ko-Aoe from Ko-Bizen: the signature is cut on the ha-ura side in bold, thick chisel strokes, and the file marks take the form of ō-sujikai. In his two-character signature, the character 利 characteristically sits slightly closer to the mune than the character 守.

Compared with contemporary Bizen work, the NBTHK consistently observes that Moritoshi's blades — and Ko-Aoe production more broadly — convey a more subdued, austere, and quietly astringent taste. Yet within this restrained character, the setsumei repeatedly note that Moritoshi's forging is tighter and better refined than is typical for the school, and that both ji and ha show thickly adhering nie and abundant activity, revealing what is termed an outstanding level of workmanship. His tachi sugata, when preserved in ubu condition — broad, with high koshizori and evident funbari — is described as bold and splendid. Surviving signed works by Moritoshi are rare, and ubu examples rarer still; accordingly, the NBTHK regards such pieces as being of particular value as reference material. His work stands as a defining expression of the Ko-Aoe manner: an archaic, sober elegance sustained by refined technique and vigorous internal activity within the hardened edge.