Futon bedding on the Tatami floor (Japanese traditional way, but with an extra mattress :).
Room size - 3.6 m x 4.2 m (12 ft x 14 ft).
With a private terrace - 1.8 m x 3.3 m (6 ft x 11 ft).
Your own private bathroom down the hallway (separate key will be provided).
If you don't mind crowding, 4 people may be possible