Among the lines that carried the idiom eastward, the occupies the ground where turns toward steel. By tradition the school began when smiths of the Fukuoka went down to in at the order of the shogunate, settling under Hojo patronage in the middle period. Sukezane, the Fujigenji of the line, leads the relocation, his name entered in the -smith genealogy of the Kanchiin-bon Meizukushi, and beside him went Suketsuna, recorded by tradition as his son; the published sources gather them under the separate appellation " " from old times, and read alongside the parallel migrations of Saburō Kunimune and Kunitsuna of Yamashiro, the belong to the generation that laid the foundations of swordmaking and pointed it toward the - to come. Kunitoshi figures among the eastern hands invited under the patronage, so that the line stands at the seam between two traditions rather than wholly within either.
The collective vocabulary the school shares is a flamboyant (華やかな丁子乱れ) forged with a strength of rather than the pure of . On a wide, robust of mid- form, the smiths forge an mixed with , the grain standing open in places (), set with thickly applied and threaded with , over which a rises with clarity. The temper carries ōbusa-chōji, , the tadpole-headed , and , the -height rising and falling, with and entering freely and a deep, bright . What separates the school from the parent Fukuoka is the activity that fills the edge: and run vigorously, mixes in, and the runs , often turning to a point or to and at times taking a flame-like form. Sukezane shows a and distinctly stronger than the other hands (他の工に比して一段と強く), his adhering closely in the ; Suketsuna reads the forcefulness further forward, tempering in the manner yet in , his grain standing more open and his temper at times tending , so that the usual flavour grows faint. It is this - blend, the base retained while the deepens, that fed the early -; where one weighs a blade thick in and rich in and , the register finds in it a coloration (相州伝的色彩) and explains why the term " " came into use.
To a blade is to read a base carrying a weight of : the bright that the later work would lose marks the smiths as masters still, while the deep active , the and threading the edge, and the pointed or point the attribution beyond the parent school and away from the quieter Fukuoka line. Sukezane stands as the most powerful of the hands and a forerunner of the smiths (相州鍛冶の先駆者), his archetype the National Treasure "Nikkō Sukezane" (東照宮日光助真), the favored blade of Tokugawa Ieyasu; the published register grades him Sai-jō , and his hand divides into two readings cut from the , a high, fine signature accompanying his most quintessential wide-bodied and a lower, rounded one accompanying gentler form. Suketsuna survives chiefly in attribution, his signed extremely few and treated as reference material for study of the name. Most of the school's great blades are and , attributed by the and at times carrying gold-inlay or red " " appraisals; the recorded provenance runs through the men who held the country, Hideyoshi, Katō Kiyomasa, and the Tokugawa among them, with the finest now kept in the Tokyo National Museum, the Tokugawa Art Museum, and Itsukushima Jinja.