Moritsugu of Fukuoka in was the son of the smith Ishido Rihei, and when his father died he went to study under his cousin Koretsugu; when Koretsugu's heir Toshitsugu predeceased his father, Moritsugu is said to have succeeded to the headship of the main line. He signed himself first Gonsabe and later Hansabe, and died in Genroku 14 (1701), aged sixty-nine. The published sources name him, with Koretsugu, the representative smith of the Fukuoka Ishido, the branch of the wider Ishido enterprise that set out in the new-sword era to recover the clove-flower temper of the old Fukuoka . They rank his school beside the branch of the line as one of the two pillars of the province's new-sword work, and on his fullest blade they write that Moritsugu's strengths are amasu tokoro naku happatsu sareta, displayed without reserve.
His recognized hand is a single manner, held with unusual consistency across the signed by which he is known. The temper is a mixed with , taken broad in , and its governing peculiarity is that the pattern overall leans the wrong way, a slant that runs counter to the upright cloves of the he otherwise looks back to. The published sources trace this reverse cant, and the nuance that goes with it in the , to Koretsugu's training under Sakon Korekazu of the Ishido, writing that ni ga ari, the forging carries a flavor. Within the enter and , the -dominant with along it, and and pass through. The single feature the published sources mark as Moritsugu's own is an edge in which the crest of a clove climbs so far that it reaches the , a broad swelling form they record as popularly called the ika no atama, the squid head; on one early blade the idea is put as cloves like a squid's bag.
The beneath this temper is an that flows strongly and, in its lower half especially, draws over toward , so that the steel reads as a coursing grain rather than a still one. Fine settles across it and, on the closely worked pieces, thread through where the grain opens. Standing in that is the trait by which the whole school is known and by which it justified its archaism: a , a cloudy reflected shadow of the temper, deliberately raised at a date when reflection had otherwise vanished from new-sword steel. It is the visible proof of the revival, the Fukuoka fetched back two and a half centuries; on his broadest blade the reflection even divides by face, a on one side and a straighter, -toned reflection on the other. The answers quietly, turning in a often brushed with , sometimes entering as a small before it rounds, now and again pointing or taking a short jizo-like turn.
The consistency of the hand means his manner is better read in two grades than as a sequence of periods. The ordinary grade is the typical Fukuoka Ishido : a blade, , with a and, against the stiff shallow curve of its -era contemporaries, a comparatively deep , which the published sources offer as itself a mark of the group's shape. The fuller grade widens everything. The opens until the squid-head crests climb to the ; within the gather , , angular and pointed elements; are set here and there and the back is freely tempered in , and the whole turns brilliant. His finest recorded blade, broad in and thick in , belongs to this grade, and it is of it that the published record speaks of his strengths displayed without reserve. A second line runs through the signatures themselves: the long inscriptions are cut in large characters with a thick chisel in a hand the published sources single out as , gyo, reisho majiri, blending the formal, running and clerical scripts, and several blades carry the added declaration that they were forged i nanban-tetsu, with imported steel, two of them dated to Tenna 4 (1684).
What sets Moritsugu apart is best drawn from his own steel rather than by contrast. The Fukuoka of tempered its cloves upright over a quiet ; Moritsugu keeps the clove and the revived but lays them over a coursing, -leaning and cants the whole pattern in reverse, so that an upright old- brilliance is recast in a flowing new-sword grammar. That recasting is the Ishido inheritance carried home to through Koretsugu, and the squid-head crest is the local accent added on top. The published sources value him at the head of the school for exactly this: a maker who could specialize in the clove temper, raise the school's reflection, and still stamp the result with a form of his own. They write of his earliest designated blade that he was skilled in the temper and showed a reflective tendency, and judge it a quintessential and representative example; of his broadest, that in it Moritsugu's true province is displayed without reserve, the squid-head edge, the deep and the wide reflective all in full relief.
Moritsugu's record stands entirely at the level, ten blades across a long span of sessions reaching from the 1960s to 2001, all signed and all , with no National Treasures or Important Cultural Properties among them and no recorded provenance attaching to any. The Nihonto Koza places him a solid step into the upper craftsman ranks rather than at the summit, and that is the honest measure of him: a representative master of a respected provincial school, not one of the great names whose blades pass between famous houses. One of the ten is a rarity, a collaboration signed jointly by Moritsugu and his son Morimasa with the supplementary line kirimono dosaku, the carving by the hand; the published sources note that, since works of the smith Yoshimasa survive bearing carvings by Moritsugu, he was adept at as well. For a collector the school is reachable in a way the it imitates is not. His signed blades come to dealers from time to time, more often than those of the first rank and recognizable at a glance by the broad reverse-canted cloves, the raised and the bold multi-script signature, so that a sound example is a realistic, if patient, acquisition rather than a thing one may only read about.