One of these spaces (specific to the Japanese interior architecture), is visible in this photo on the left of the far-side wall. Called tokonoma (from toko, "floor" and ma, "space"), it is an alcove used to display ikebana arrangements or hanging scrolls. The raised floor indicates a sacred place and stepping inside is not allowed.
On the right side of the same wall, you can see another alcove, for storing small objects: books, tea utensils, small trays, incense burners... The split-level shelves are called chigai-dana (from chigai, "different" and dana, "shelf"), and above there's a tenbukuro, a small cabinet with sliding doors.
EXIF info:
Nikon D700
Lens: 14mm F/2.8D
Focal Length: 14mm
Aperture: F/4
Shutter Speed: 1/60s
ISO Sensitivity: ISO 2000