Sanetoshi, the name read Mari and cut as the two characters 真利, is a Bizen swordsmith of the early Kamakura period, placed by the published sources among the Ko-Ichimonji, the founding generation of the Fukuoka Ichimonji that the school's progenitor Norimune leads. The Tokubetsu Jūyō tachi that is the centre of his record carries that two-character signature on an almost untouched tang, cut with a somewhat thick chisel above the original mekugi hole, and the judges read it from form and steel as a Ko-Ichimonji work of the period's first decades. The published commentary describes these earliest Ichimonji hands as standing apart from the school's later splendour, holding instead 'an old Bizen character strongly preserved' in both shape and the workmanship of ji and ha. Sanetoshi belongs at that root, before the great flowering of the school at Fukuoka.
The characteristic hand sits deliberately between two poles. Over an itame mixed with mokume, the grain standing a little toward hada-dachi, he lays a temper that is no longer the plain ko-midare of old Bizen yet not the high clove-flower of the mid-Kamakura school: a chōji and a suguha-toned ko-midare into which he mixes ko-chōji and ko-gunome, ashi and yō entering well, ko-nie adhering, with fine kinsuji and sunagashi threading through. The published sources name this balance exactly. Set beside Ko-Bizen, they write, 'the chōji stands out more and shows a slight air of technical sophistication'[[c:1]]; set beside the mid-Kamakura Ichimonji, the same work 'is calmer, presenting an archaic and elegant taste'[[c:2]]. The conspicuous ko-chōji on a quiet base is the tell of the hand.
The jigane is the constant beneath that temper. On the signed tachi the itame and mokume carry fine ji-nie and chikei, and a midare-utsuri stands out clearly across the ji; on the kodachi the ji-nie gathers dust-fine and thick and the utsuri rises a little fainter. The reflection of old Bizen steel is the feature he keeps on both blades, the Fukuoka jigane he shares with the school. The bōshi runs nearly straight to a ko-maru, on the kodachi finishing as a yakizume with hakikake on one face, a quiet ending that suits the archaic register.
His surviving work divides into two manners that the judges read as one hand's range rather than two careers. The prime is the ubu, two-character signed tachi, dignified and rather wide, the chōji at its most pronounced over the standing itame; the Tokubetsu Jūyō piece, its signature clear and its ji and ha sound, the commentary calls 'a fine work, rich in points of appreciation'[[c:3]]. The other manner is the quieter work of the slender, suriage kodachi, fundamentally a chū-suguha with ko-chōji, ko-midare and ko-gunome and frequent ashi and yō, archaic in taste, yet with the ko-chōji conspicuous enough to show a degree of technical artifice. That kodachi the judges find 'appropriate to appraise as the work of Mari of Ko-Ichimonji', a particularly distinguished piece for the strength of its nie and the variety of its activity.
The central scholarly question is the name itself. The Meikan records 真利 across four groups, Ko-Bizen, Fukuoka Ichimonji, Katayama Ichimonji and the Osafune line, and a comparatively substantial number of works survive, yet the published sources caution that 'it is difficult to distinguish these clearly on the basis of signature style alone'[[c:4]]. Signed Mari blades whose own published texts place them with Ko-Bizen or with the Osafune hand are kept under those smiths, and his Ko-Ichimonji attributions therefore rest on era and school manner, on the sugata and the ji-ha, not on the shared mei. The judges set him apart from the later school by exactly the words they use of the early generation, that their work, 'unlike the splendid style of the mid-Kamakura period'[[c:5]], keeps 'an old Bizen character strongly preserved'[[c:6]]; and apart from the plainer Ko-Bizen smiths by the brightness of his midare-utsuri and the gathering of chōji on his edge.
For the collector he is a rare early Bizen name. Fujishiro grades him Jō-jō saku, and the Tōkō Taikan value of 900 places him among the well-regarded Ko-Ichimonji hands. He has no National Treasures and no Important Cultural Properties. Two designated works are on record, both in the Tokubetsu Jūyō and Jūyō tiers: the ubu signed tachi, designated Jūyō in 1992 and raised to Tokubetsu Jūyō in 1994, and the signed kodachi, designated Jūyō in 2006. His provenance reaches into the great northern daimyō house, for the Tokubetsu Jūyō tachi descends from a branch family of the Yonezawa Uesugi count household. No current institutional holder is on record. A signed Ko-Ichimonji Mari comes to light only seldom, and most of what survives is held rather than traded; a privately held example is a notable thing for a collector to encounter, a document of how the Ichimonji began.