A very, very rare, antique, samurai's Mune-Ate
Samurai wore over their armour a Jin-Baori (War Haori surcoat), a Mune-Ate (Dickey for front of dou [dou = torso armour), each bearing their mon (crest), and a Hachimaki (Hair Band). Some were made of rugged material and some, like tis piece, were for more ceremonial occasions and made from fine silk.
This piece is from the Edo era (1603-1868). The end of samurai in Japan was 1868