The Bamén (場面) school is famous for the emergence of Tsunemasa 序政, who brought innovative artistry to sukashi tsuba . The name "Bamen" can also be written as "馬免" (horse-face), and originally referred to a group of helmet makers and blacksmiths whose origins date back to the Sengoku battle age period. This family resided in Echizen Province (present Fukui). The name "Bamen" was bestowed by the ruling Honda clan. Many members of this family worked as blacksmiths, crafting agricultural tools, helmets, and firearms in Maruoka, Echizen, until the end of the Edo period.

 Tsunemasa 序政, common name was Ichijūrō 市十郎, was born in 1741 (Kanpō 1) and to have lived in the late Bunka period and early Bunsei period. He resided in Shitaya, Okachimachi.

 He signed his works as "Bamen Tsunemasa (kaō)" to the left of the seppa-dai. His works are dated to the fifth year of Kansei, the tenth year, and the sixth year of Bunka, among others. Some of his works carry age notations indicating he was 68, 70, 72, 73, or 75 years old. His signatures sometimes include place names, such as "Bushu jūnin Bamen Tsunemasa" or "Made with Nanban iron."

 Tsunemasa 序政 specialized in crafting iron circular tsuba using both in-sukashi (negative openwork) and yō-sukashi (positive openwork), creating designs that resembled shadow pictures. Contemporary sukashi tsuba schools included Akasaka, Akao, and Bushū Itō schools, but Tsunemasa adopted his best elements and refined them into his own aesthetic, influencing the sukashi tsuba style of various schools.

The iron work of his tsuba is exquisitely forged, and the designs are outstanding. His sharp use of chiseling, especially in the shippō pattern, stands out as exceptional.

Mid-Edo Period