The correct size for women's kimono is your entire height (from head to floor) so you can wear it fashionably with an ohashori (the fold at the waist). The correct height for men's kimono is your height from your shoulders to floor. Men's kimono is not worn with an ohashori. Some dance kimono are longer than your entire height so they can trail nicely on the floor and look glamorous when you move. Maiko and geisha's kimono are this type, called hikizuri. Because these sizes are exact (i.e. your height, your shoulder height, et cetera) kimono is not really one size or "free size". It is tailored to your measurements, so when buying secondhand you must check the height and the size of the back and front widths to make sure it will fit you properly. Of course there are mass-produced yukata now that are sized like S, M, L, LL, and so on, but unless you are the exact size they think of when making that size, it won't really be properly measured to you. (Of course, they are still wearable.) To use the toilet, it's quite simple to pick up the layers from the hem and pull them up above your hips, so you can sit down and use the toilet. Once you are done, it's easy to put each layer back nicely, so it's as it was before. For hakama, the back is tied on last, so you untie the back only and fold it down, leaving the front still tied, then pull up your layers as described. It's easier when wearing hakama because you wear your kimono a bit shorter. Please recall that traditional toilets are squat toilets, so this holding of fabrics out of harm's way is a bit easier with that style, but it still works with a sitting toilet.

Yes, I can✨

It's not a specific character. This is the attire for performing the HANAnoKOTOBUKI, a dance from my school of performance