Here we have the "Kuromontsuki haori hakama"
'Haori' refers to the light coat, and 'hakama' refers to the loose trousers.

The haori here is made with 'habutai', one of the most basic weaves of silk.

The hakama is made from sendaihira, a silk originally from Japan's Sendai area.

This outfit features black Habutai, dyed five-kamon nagagi and haori matched with Sendaihira hakama. Such clothing is called the first dress, as well as the male highest rank clothing, which is widely used on formal occasions such as weddings, coming-of-age ceremonies (seijin-shiki), funerals and so on.

Here is the "Iromontsuki haori hakama"
This features a colored habutai haori, with nagagi and Sendaihira hakama

This is a high-rank dress for various formal occasions other than funerals, such as weddings, age ceremonies, etc. Compared with the kuromontsuki haori hakama above, it is a relatively casual dress style. There are three types for the number of kamon of iromontsuki haori hakama, those are five, three and one, the fewer the number of kamon, the lower the rank, so on formal occasions, please wear a formal kimono with five kamon. (Formal Japanese emblems)

The rank of haori hakama is lower than the iromontsuki haori hakama, and there are two kinds of fabric of haori・nagagi:

The number of kamon of haori hakama is usually three or one, the omeshi is more formal than tsumugi.

Phew, that's a lot of Japanese! Here's a quick index:
Kamon: family crest / emblem
Haori hakama: Coat and trousers
Omeshi: Silk crepe kimono
Tsumugi: woven kimono

For the hakama, the Sendaihira hakama, plain omeshi hakama, or tsumugi hakama can be chosen freely. But the kimono made by tsumugi does not match with the glossy types of hakama such as Sendaihira.

Here we have "nagagi," which is a type of kimono that doesn't involve trousers.

Just like haori hakama, the fabric of haori clothing can also be divided into two types, omeshi and tsumugi. Combine the haori and nagagi according to your own preferences, you can go out in fashion but not lose rank.

On more casual occasions, you can wear a kimono without a haori coat. This is known as kinagashi, and is completely formal. This is perfect for those who just want to casually try out a kimono for themselves!

Illustrations courtesy of Manga de Japan