Space is notoriously compact in Japan so we resigned ourselves to the idea of a double bed in at least some of our lodging, but in searching hotels and apartments online, I discovered a nasty little trick called the “semi-double” bed. The first time I came across this term, I’d clicked on a listing for a “double bed” room that seemed like a surprisingly good rate. Getting right down to the booking stage, I saw the phrase “semi-double.” This was new. The listing had only said “double.” Having no idea what the term meant–but feeling suspicious–I did a little research. Sure enough, a “semi-double” is basically somewhere between a single and a double or full bed in width (110-120 cm), i.e., a somewhat bigger single bed. A double bed is usually around 140 cm and a twin around 90 cm.