The of the Monju (文珠) line all gather around a single figure: Shigekuni (重国), the smith better known by the appellation Nanki Shigekuni (南紀重国). The records describe him as originally of Yamato Province and a late offshoot of the group (), whose common name was Kurōsaburō. During the Keichō era (1596 to 1615) he entered the service of Tokugawa Ieyasu and forged at Sunpu, in present-day Shizuoka; then in Genna 5 (1619), when Ieyasu's tenth son Tokugawa Yorinobu was transferred to Wakayama, Shigekuni accompanied him and settled at the foot of Mt. Meikō (also read Myōkō). The themselves carry the school name: one is signed "Kishū Meikōzan Monju Kurōsaburō Shigekuni," fixing the Monju appellation to this workshop. The corpus belongs almost wholly to the and early () period, with dated works ranging across Genna 7 and 8 (1621 to 1622). One entry raises the question of a smith named Kunimune, a close relative who remained at Sunpu, and a later speaks of a "second generation onward," so the records permit a Monju succession without resolving its members.
A shared technical vocabulary runs through every blade, and the consistently divide Shigekuni's hand into two modes. The forging is a flowing , mixed with and inclined to and , tending to stand (), with thick and frequent over a bright, clear steel. In the Sōshū-den mode the temper is a of mixed with , angular and -like elements, deep , strong that breaks down into , and conspicuous and ; the records read this manner as a private study of the high masters, naming Gō Yoshihiro above all, with Masamune and Sadamune also invoked. In the mode the temper is a , at times shallow , carrying , , and along the , which the tie directly to the inheritance and the manner of Kanenaga. The across both modes turns or with vigorous ; and show pronounced , often carved with , , and . The records present these as two facets of one hand rather than competing lineages.
For , the name several recurring markers: the bright, clear quality of both and held up as Shigekuni's hallmark, the pronounced of his - and , that coil into a whirlpool configuration within the temper, and the large original met among -domain works. One Sōshū-den is judged close in character to Batetsu (馬徹) and treated as a likely model for that smith, raising its documentary weight; another work's "Monju-style" is said to anticipate the tendencies of the second generation. The blades carry firm provenance: a made to the command of Matsudaira Shima no Kami Shigenari, a piece commissioned by the domain elder Kageyama Tosa-no-kami Munenobu, and a sword inscribed for Yorinobu's retainer Tsuzuki Tōichi, alongside a held in the Imperial collection. The note that nearly all of Shigekuni's Sōshū-den blades survive , so the examples gathered here are repeatedly singled out as research material. Across the records the Monju name stands as the continuation of a Yamato root, carried into the age in the service of the Tokugawa house.