TreeHugger has shown many ways to hide the bed; most are designed to gain more space. But the Red Nest by Paul Coudamay doesn't; the bed is still there taking up space, but is hidden by the sliding bookcase.
Oliver Peake: Japanese Bed “This was an interesting commission. The client wanted an entirely sunken bed with hidden storage and invisible heating!" I prefer more traditional storage, but love the idea of the sunken bed!