Mempo

Mempo (also menpō, mengu  or occasionally men yoroi ), is the term for various types of facial armour worn by the samurai class and their retainers in feudal Japan. Types of Japanese facial armour include the somen, menpō, hanpo and happuri.

Description
Mempo were facial armours which covered all or part of the face and provided a way to secure the top-heavy kabuto (helmet). The Shinobi-no-o (chin cord) of the kabuto would be tied under the chin of the mempo. There were small hooks called ori-kugi or posts called odome located on various places to help secure the kabuto's chin cord. Mengu may be constructed from iron or leather, or a combination of both. They may have a lacquered or rusted type of finish and can include a variety of facial details, such as moustaches, fierce teeth and a detachable nose. Most mempo with the exception of the happuri had a small hole underneath the chin for sweat drainage.

Mempo are similar to masks worn by armored cavalry and infantry in ancient Chinese armies from the Han Dynasty to the Song Dynasty.

Somen
Somen covered the entire face

Menpō
Menpō covered the face from the nose down to the chin.

Hanbō (hanpō)
Hanbo covered the lower face from under the nose to the chin.

Happuri
Happuri covered the forehead and cheeks.