Nio dou gusoku, one of the rarest styles of samurai armor crafted during the Edo Period, named after the Nio Guardian figures in Japanese temples. There were a number of meanings behind this style. One being it's close association with buddhism. The dou is embossed to resemble the emaciated torso of a starving monk or old man. These are also called "gakihara dou", after the starving ghosts of buddhist hell, another example is housed in the Tokyo National Museum.