Season theme

[parfaitelumiere]

Hello,

I am wondering if a koshira must have all parts matching same season?

I saw several popular theme, chichi botan, bell cricket, and other themes, these must be season theme.
Is it like kazari, or women clothing?
Is it like the kakejiku, or other things used for ceremonies, or just season thee?
In this case it means the swords had many different ferrules, at least one set per season and probably one set for special occasions (plain shakudo tsuba, karaigi saya and horn kashira)
I found a daisho set, the mount doesn't seem to be so recent work, tsukamaki seems to be quite old, F-K are aoi plant and menuki are, I think chrysanthemus, not sure, quite difficult to find the actual plant names, for example I didn't find the scientific aoi plant name.
All seem to be real daisho set, not saya from somewhere, and tsuka from somewhere else, only the tsuba were recently paired with mounts.
So I am looking for a tsuba set, but want to know more about how to match, if there is a seson theme to follow.
And in general, I wanted to know more about season theme on ferrules and koshirae, it should also be interesting to list here the species, animas and plants used as season theme, as this is my main Japanese painting collection them.

[MauroP]

Just a little of selfpromotion about themes in tsuba  😉
https://www.dropbox.com/s/frt7dkpoj6b5x8y/FHJ.pdf?dl=0
https://www.dropbox.com/s/7cgrf6pfluf15xw/Tsuba%20-%20Kodogu%20Gadai%20Jiten.pdf?dl=0