Auxiliary Armor

Intro
Auxiliary armor are armors that are not considered the main line of defense traditionally. They are often allowed to be made out of thinner material and sometimes can even take advantage of some Gusoku Exemptions.
It is important to note that not all the pieces of armor here are used at the same time. Some would be in direct conflict.
There are some armor pieces that we consider Auxiliary:
Manchira/Tate-eri
Manchira are a type of armoured vest covered with different types of armour including kusari (chain armour), karuta (small square or rectangular armour plates), or kikko (hexagon plates), sewn into a cloth backing.
The advantage of this armor is that it covers the gaps intentionally left open on chest armors. Effectively covering the under armpit area and gap between shoulder and neck. It may be easiest to think of a Manchira as a combination of both a Wakibiki and a Tate-eri (descriptions below)
Tate-eri are like manchira, but they only offer protection and padding for the shoulders and lower neck. 
If a Manchira utilizes armor that would be classified as leather-tier: It cannot be worn alone. However if it is worn under chest armor that is plate/chain tier, then it is allowed under the Gusoku Exemptions.
mc.png|Manchira coverage
1024px-Kikko_manchira.JPG|Manchira example
Kikko example.png|Tate-eri example
2028629577a6c756e83ba710ae896d0c.jpg|chain manchira example
tate-eri-TTE-white-black-200x200.jpg|Tate-eri example
Wakibiki
Wakibiki are simple armor items that you wear under your dō, they hang from your arms and offer armor coverage to the gaps under your armpits.
1280px-Kikko_wakibiki.JPG|Wakibiki example
1024px-Kikko_wakibiki_3.JPG|Wakibiki coverage area
Nodowa/guruwa
Nodowa and guruwa are similar types of neck protection, the nodowa would be tied around the back of the neck and the guruwa wrapped completely around the neck. They offer lower-neck and upper-chest protection. Nodowa are slightly different from the throat protection offered by Mempo (Face armor). (The mempo throat protection is called Yodare-kake)
Guruwa,_throat_and_neck_protector.JPG|Guruwa example
Nodowa_1.JPG|Nodawa example
Men-yoroi
Men-yoroi are Japanese face armor. They are often accented with neck protection (Yodare-kake) but don't have to be.
Sometimes face armor has various categorical names such as Mengu. For generic purposes there is no real appreciable difference.
There are differing styles of face armor:
# Menpo - Facial armor that covers the cheeks, chin, lips, and nose. It is often paired with Yodare-kake (throat protection)
# Happuri - Facial armor that covers the forehead and cheeks.
# Hanpō - Facial armor that only covers the chin and cheeks. It is often paired with Yodare-kake (throat protection)
# Sōmen - Full coverage facial armor. It is also often paired with Yodare-kake (throat protection)
# Hachigane - An armored headband.
800px-MAP_Expo_Somen_02_01_2012.jpg|Somen example
genuine-authentic-edo-period-samurai_360_c8817a7cc00ac8058f7b58fa321f52be.jpg|Hanpo example
happuri_by_shimaha_d5gwbz2-350t.jpg|Happuri example
mchachi.png|Hachigane example
39998674_2119647698287970_212176963584917504_n.jpg|Menpo example