A dated the eighth month of Ōei 20 (1413), handed down in the Ōshimazu family of Satsuma and raised to at the twenty-sixth session, is signed in two lines Minamoto Saemon-no-jō , and within the character the interior is cut as the character for "left." That reversed form is the first point the published sources give for this hand. The opens its account with the house: 「信国は京鍛冶の名門で、南北朝時代から室町時代にかけて大いに栄えた」 ( was a distinguished Kyoto house of smiths that flourished greatly from the into the period). In the branch Saemon-no-jō and Shikibu-no-jō are the representative smiths, and because both cut Ōei dates they are admired together as the Ōei . The line descends from Ryōkai and so from the , and its first generation is said to have studied under Sadamune; his works of Enbun and are the oldest dated pieces, and the Ōei smiths are reckoned the third generation. Tradition makes Saemon-no-jō the elder brother, but the published sources observe that among known dates the signature of Shikibu-no-jō is in fact the older, and they leave the relationship of the two to future research.
His most constant feature is carving. The published sources state that Saemon-no-jō and Shikibu-no-jō alike 「濃厚な彫物を得意としている」 (excel at dense carving), and the record bears it out. Flaming , a in relief within a or pierced through it, and , hata-, lotus pedestals and the invocation cut into the groove recur on both faces, often layered one over another. Of one the judges write that the and are ordinary but the pierced in its is splendid. The temper he made his own is the second mark. Every generation of , the published record explains, worked chiefly in two manners, a showing the Kyoto tradition and a inherited from Sadamune, and from the late generation into the Ōei smiths 「互の目主調の乱れ刃の作域を新たに見ることが出来る」 (a working range of -ba led by can newly be seen). Its idiom is a that runs in pairs. The sources describe 「互の目が二つずつ矢筈形に連れた特色ある刃文」 (a distinctive in which the run two by two in the shape of an arrow-nock), mixed with angular and pointed teeth, and -like elements. and enter, the lies thick, and run through the , and and gather over the crests under a bright .
Beneath both tempers lies one . It is an mixed with , flowing in places into toward the edge and tending to stand, with thick and frequent ; where the forging tightens it becomes a . The that keeps the Kyoto tradition is the rarer face of his work. It runs narrow to medium, at times with a little , and entering, well adhered and the fraying in places with and ; the runs straight to a with . On the Ōshimazu the judges call that 「匂口明るく刃中よく働き」 (bright in the and full of activity within the ). Of an Ōei in they draw a comparison: 「応永備前も直刃の作を好んで焼くがやはり信国の方が沸が強いようである」 (Ōei too likes to temper , yet seems the stronger in ). Another judgment holds that 「この時代の信国には直刃の出来は珍しく」 ( work is rare among of this period), and a large tempered in with a tight is said to recall work.
Most of the record is and , with and somewhat extended in length, a build one judgment likens to Ōei . Signed are few. A dated Ōei 2 (1395) and a dated Ōei 4 are assigned to the who worked from the close of the previous age into early Ōei, and their dates are called valuable material for the study of the school. Further dated pieces of Ōei 15, 20, 21, 30 and 34 follow. On the Ōei 34 , a prewar , the published record notes 「丁子乱のにぎやかな刃文」 (a lively ), unlike the . A Shikibu-no-jō in is called a temper rarely seen in his work, perhaps made with the senior Kyoto school of Hasebe in mind. The signature completes the reading. The name carries the family Minamoto, so the smith commonly called Genzaemon-no-jō is properly Minamoto Saemon-no-jō, and his is known by its reversed interior, a form the sources trace from Shitoku and Meitoku and find common in Ōei. Honma's inventory of the Imperial collection adds a caution, that this form 「必ずしも源左衛門尉に限ったことではなく、後代信国にも見るところである」 (is by no means confined to Minamoto Saemon-no-jō but is also seen in later ), so the workmanship must be weighed together with the . One with the reversed is accordingly left undecided.
The first , the published sources write, was a pupil of Sadamune whose work 「殆んど師貞宗に迫る作風を示している」 (shows a style that comes close to that of his master Sadamune). The Ōei generation carries that into its paired while keeping the bright Kyoto , and his own combination is what sets him apart: the running in pairs, the standing that flows toward the edge, the strong , and the layered devotional carving. The sources also record that other smiths cut a two-character in the same years, so that several namesakes are thought to have worked side by side, and unsigned or plainly signed pieces are referred to Saemon-no-jō or Shikibu-no-jō by the cut of the and the manner. The line later spread, one branch moving to Bungo in Kyushu and signing with a further name. Honma also notes that the ends in a round from the first generation to the last, unlike the -shaped tang of Sadamune.
Fujishiro grades the Ōei Jo-jo , and forty-four designated works stand on record. There are no National Treasures. One Important Cultural Property, a signed as a dedication to the Hongū Sengen shrine by Minamoto Shikibu-no-jō and dated Ōei 24 (1417), is kept at that shrine. One blade holds rank and thirty-nine more the , forty in the two tiers together; the Ōei 34 is a prewar once held by Tokugawa Munetaka; and two blades, a and a , are recorded in Honma's inventory of the Imperial collection. Forty-three of the designated works are signed and only one is unsigned. Recorded provenance runs through the Ōshimazu of Satsuma, the Tokugawa shogunal house and the Owari Tokugawa, Hosokawa Tadaoki and the Kuninomiya family. A of the Kenshō-in at Tōnomine was presented by that temple to the shogunate at the succession from Ietsuna to Tsunayoshi, Tōnomine offering one sword from its treasury at each change of shogun. Of recorded whereabouts, examples rest at Atsuta Jingu and Jingu, the Tokugawa Art Museum, the Sano Art Museum, the Kurokawa Research Institute and the Kyushu and Kyoto National Museums. For the collector the Ōei is a name within reach of patience: signed and of the tier come to market from time to time, while a signed , which the published sources call 「頗る貴珍」 (exceedingly rare and precious), appears only rarely and is an occasion when it does.