My Wife's Secret Mattress

After Shion Nishina buys an expensive mattress, she stops sleeping in the same room as her husband, Yuma Kazaki. Yuma assumes she is simply short on sleep and resting elsewhere, but he slowly notices something strange about her nightly habits. Each night she spends time alone with the mattress in ways that are hard to describe, and her unusual devotion to it raises questions about what she is hiding. The mystery of that bed sits at the heart of this high-society thriller.