IKEA Semi-Double Mattress VATNESTR?M

Price reduced to ￥8,500 for direct pickup in Shibaura, Minato Ward.

Purchased new 2 years ago. Used with a mattress cover. There is some slight staining on the upper half, but it does not affect usability.
Non-smoking, no pets.

Below is the official description.
This mattress has three carefully considered features. First, natural materials absorb and quickly release moisture. Latex, coconut fiber, cotton, wool, etc., maintain a constant temperature within the bedding, allowing for very comfortable sleep. Second, it has 5 comfort zones. It reduces strain on the spine, making it recommended for those suffering from back pain. Third, the edges are reinforced, so it doesn't sink even when sleeping near the edge. This allows you to use the mattress more widely, and even when placing two side-by-side, the seams are not noticeable. Once you experience this mattress, you won't be able to help but tell others about its comfort.