Like any kind of craftsmanship that’s been around for centuries, kimono-making has built up an enormous vocabulary to refer to the various parts of a kimono, the various types of kimono, and the techniques used for creating them. I do not want to overload you with new terms in a language you may not speak that are so hyper specific. That being said, I found it was helpful to learn some of the terms for certain parts of a kimono because they stick in my mind and remind me of their importance – things I should be mindful of while I’m in the process of making garments. There are many places on the internet detailing every single term associated with the kimono construction, but I find them a little overwhelming. The diagram below might be helpful for you. These were terms that were helpful to me.

Sode-yama and kata-yama: Yama means ‘mountain’, and so the sode-yama is the sleeve mountain and kata-yama is the shoulder mountain. I find both these terms useful and worth remembering because these folds, either ironed in or marked in in some other way, are incredibly important to the construction of either a kimono type or a haori type garment. They each represent the half-way mark of the fabric piece and stand in for a shoulder seam in western garments.
Eri and tomo-eri: These are the collar and the collar ‘friend’. I just loved the idea that a collar would have a friend. It anthropomorphises the garment in a delightful way. In kimono or yukata construction the tomo-eri is placed on top of the eri, with a graceful little tuck at each end. This collar’s friend can be removed if it gets worn or too grubby exactly where skin oils, sweat or contact is most likely to mark the garment, and reveals a new, pristine collar. Haoris traditionally don’t have tomo-eris but I often add them to the collar of those garments too because it just tickles me for them to be there. Maybe they deserve a friend too?
Se: This is the back seam/centre lengthwise fold of the garment. Its importance is similar to that of the two ‘yama‘ folds; lacking a paper pattern, it is vital to orient the construction of the garment, most especially the spot where you place the collar’s midpoint. The se has a lot of symbolic weight, also. Long before the evolution of the kimono, the se was, and still is, an element in the construction of all traditional Han Chinese coats, jackets and shirts too. It is the spine of the garment and carries a sense of rectitude, integrity and uprightness.
Sode and migoro: The sode just means the sleeve. The migoro refers to the body pieces of the garment, both front and back.
Okumi: These are the two front flaps sewn onto the migoro on either side to widen the front pieces of the garment so your legs aren’t exposed as you walk. I have found that it is useful to think of this particular pair of pieces as more flexible width-wise. If you’re making a garment for someone with quite wide hips, increasing the width of the okumi, either by minimising the seam allowances or actually cutting the pieces a little wider, can really help to address the reality of the human body.
Uchiage and miyatsu-guchi: these are parts of the kimono that are traditionally gender-specific. The uchiage is a seam, sewn across the back and front panels of the body pieces to hide the excess length of the migoro. This is traditionally only done for male garments. But what I imagine is that perhaps a kimono is made for a teenage boy, and as he gets taller, the uchiage can be unpicked, and more length can be added to the robe. Conversely, as a person ages and loses some of their height to spinal compression, the uchiage can be a place to store that excess length while not cutting any excess away – because that kimono might be handed down to someone else. The miyatsu-guchi is where the sleeve is not joined to the body piece, but finished and left open to allow for someone to reach in and adjust the undergarments or obi ties. It traditionally only appears on women’s garments but I find it one of the most heart-tugging and graceful parts of a kimono. It’s lovely for ventilation, and if the garment is lined, it offers a pretty peak at the lining. It is also, like the high side-slits on a Vietnamese ao dai, a seductive little window onto skin.
I am explaining what’s traditional, but my personal ethos when it comes to making garments is not one of absolutism or nostalgia. I almost always construct a miyatsu-guchi in a kimono I’m making for a man, because it’s simply a delightful aspect of the garment. Why shouldn’t men have it? On the other hand, I will often close the seam where the sleeves and body meet on haoris I’m making for either gender if they are meant to be worn for warmth. Because those openings can be a little draughty!
Similarly, because I sew my kimono for women without the extra length that is used to hike up the skirt beneath the obi, if I were constructing something for a young person of either gender, I would most definitely add some length to the height measurement, and construct an uchiage for them so that, as they grew, the garment could be lengthened to celebrate growing taller.