This is a used J-Life All Cotton Shikifuton, a Japanese floor mattress, in good condition. Equivalent to a twin size.

We used it as a floor sleeper for our toddler, always had a water proof cover on it, but are now moving and won't be using it any more. We regularly slept on it with our toddler, but it was definitely not our style, just too firm, though putting a mattress topper on it did help considerably. The main issue I think is that traditional futons like this are supposed to be aired out and fluffed up outside in the sun year round, and require maintenance to keep them breathable. We pretty much just never did that lol. This is probably a great sleeping option for someone wanting a traditional futon sleeping option, and is willing to do that maintenance on it.

Feel free to reach out with any questions.