Yoroi - Yukonoshita

Tōsei gusoku armor in the Yukinoshita dō style, Edo period (1603 - 1868)

The armor consists of a five-piece Sendai dō cuirass, a 32-plate sabiji Suji bachi kabutō, with a large maedate in the form of a gilded circle (ensō), long fukigaeshi with an abundance of mimi ito and a decorative agemaki knot on the ring on the back of the helmet bell. The mempo is in the me no shita bō style and its tare has -like the sode and kusazuri- dark blue lacing, complemented by decorative mimi ito . The armor is completely black lacquered, except for the sabiji kabutō, which is typical for Sendai dō. The kote armor sleeves and suneate shine protection are in the tsutsu style, on the back plate of the cuirass there is a holder for the personal banner sashimono gatari with an inserted tube for it uke zutsu.

The inventor of this type of armor, which was considered one of the highest quality  the late Sengoku period, was Yukinoshita Masaie, originally a lantern maker in the Aizu domain. Masaie created a new concept of armor with minimal lacing and the connection of the five segments of the cuirass to the hinge. This type was able more effectively stop bullets from the new weapon that shaped battles in the late Sengoku period - the musket. When the famous warlord Date Masamune 伊達 政宗(1567 - 1636), nicknamed the "one-eyed dragon", became acquainted with this unique type of armor, he was delighted and had all his vassals equipped with it. He himself also used one of these armors.

This type of armor is said to have inspired the design of the armor costume of the character Darth Valder from Lucas's Star Wars.

Yukinoshita do gusoku has an alternative name Sendai do gusoku because in 1604 Masamune moved the center of his domain to Sendai, which he soon greatly improved.