I found this while cleaning out my parents' house. I think I bought it about 5 years ago. It's made of polyester, so it's washable and easy to use. I've used a similar one, and it's warm, feels good against the skin, and is easy to put on. Thank you. I also have another one of the same item that I only wore about 4 times last year, over my pajamas before bed, and haven't washed yet. If you'd like to purchase that one as well, I'll sell both for 1500 yen. Please leave a comment if you're interested, and I'll adjust the price.