There are two (2) Muji "Futons" (floor beds), one fitted (elastic) sheet that wraps around the futon, and the other sheet is thicker but covers the top and stays fastened with elastic bands.
I'm also providing a futon-sized memory foam mattress topper for free.
The original information for the futons can be found here: https://www.muji.com/jp/ja/store/cmdty/detail/4547315119134
They are actually quite comfortable and expensive, but will feel different if you are used to the typical American bed. Both mattresses do have a velcro strap if you wish to join the two together.
The fitted sheet is blue and a gauze-like material (the original can be found here) : https://www.muji.com/jp/ja/store/cmdty/detail/4550182925371
(they don't sell this color any more, but this is the same one)
The other elastic sheet is also blue and can be found here: https://www.muji.com/jp/ja/store/cmdty/detail/4547315119288 although has a slightly different looking pattern.
Please note that we are cat people, while we will do our best to clean it of any cat fur, it may bother some who are sensitive to cats. There may also be strings poking out where cat claws may have left. These probably won't bother most, but some people may be bothered by some loose strings.
I would prefer to sell them all together, but you can message about individual items if you like.