Russet-iron Suji-kabuto (ridged helmet) with thirty plates

This helmet bowl is a suji-kabuto (ridged helmet), carefully constructed from thirty well-forged, substantial hagi-ita (individual iron plates forming the helmet bowl) with a natural russet surface. The rivet heads have been filed flush on the exterior, while examination from the inside reveals five haridome-byō (retaining rivets) in each vertical row.
　
The sides of the bowl rise almost vertically, while the back has a slightly rounded profile, recalling the akoda-nari (squash-shaped) form seen around the middle of the Muromachi period. The shiten-byō (four standing rivets) and hibiki-no-ana (small holes associated with them), positioned relatively low on the bowl, are also characteristic features that identify it as a Muromachi-period suji-kabuto. Of the kasa-jirushi-tsuke-no-kan (ring for attaching an identification flag), only the chrysanthemum-shaped rivet head remains.
　
The interior is covered with gold leaf, and the signature “Fusanobu” is inscribed along the rear center line. An old paper label attached to the helmet reads: 明珍房信　信家弟子藤吉　上州住天文頃 “Myōchin Fusanobu, disciple of Nobuie, Tōkichi, resident of Jōshū, around the Tenbun era.”
　
The helmet has a particularly well-proportioned and compact form, complemented by the fine quality and character of its iron. Signed helmets by Fusanobu (房信) are extremely rare, making this an exceptional example.