This armor set was passed down in the Ozaki family, vassals of the Matsudaira Clan. The Matsudaira ruled in Oshi Province (present-day northern Saitama Prefecture) during the 17th century (part of the Edo Period). The armor in this set is lamellar armor constructed of small iron plates called kozane with a black lacquer coating and laced together in rows. Vermilion thread laces most of the kozane together, but white thread is used on the sleeves. The helmet is made in the shijūhachiken-suji style consisting of 48 plates. The helmet also features a horn-like decoration called a kuwagata (named for its resemblance to the head of a stag beetle). In between the two branches of the kuwagata, there is a diamond-shaped decoration; this decoration is actually a crest that could be used by all branches of the Matsudaira Clan. On the armor case (the box in which the armor was stored), there is a crest of creeping woodsorrel leaves inside a circle to represent the Ozaki family.