When you take off your kimono, hang and dry it out of direct sun light. Use a hanger dedicated to kimono, and don’t you standard hangers because those make the shoulder of kimono getting out of shape.
The reason for drying out of direct sun light is to remove the moisture trapped in fabric while wearing, so it is enough only for several hours. If it is a long time, it may cause to get out the lining from proper position with respect to the outer fabric: it also causes discoloration due to the sun light.
When the kimono is dried enough, it is better to fold it over as soon as possible. While drying, please shake of dust.
Please wash gently with a soft cloth and use a soft brush. During the old days, I was told to wipe the collar with benzene but it won’t get that much dirt if you only wear it once in a while. You might damage the Kimono if you fail so I cannot recommend it due to the risk and the effect.
Request the cleaning with a professional. The go clothing store will introduce one if you consult with them. The cleaning frequency would differ depending on the number of times it is worn, but please think of it as a lower frequency compared to ordinary clothes.
Kimonos are prone to damage when washed.