The capsule hotels are one of the things that we can only find in Japan. They are a type of hotel that arose with the need to stay to sleep near the stations, for a few hours, before taking a train, but today they are also a cheap type of accommodation for backpackers or curious tourists.
They do not stop being a kind of individualized bunks, stacked next to each other and on top.
We tried to find a double and mixed in Tokyo and it was quite difficult, most are individual and although the hotel allows the accommodation of men and women (there are exclusive for each sex), they are usually divided by plants, so the solution was to sleep every one on a hotel floor or forget about the experience of sleeping in a capsule, at the end we find one that has double and mixed capsules: Tokyo Kiba Hotel.
Capsule hotel
Double room in a capsule hotel
The experience is good in general, if your are not claustrophobic or sleep badly. The bad if you are used to "normal" hotels, is that you have to leave your luggage on the first floor in a box office and that the bathroom is not on the same floor That's the rooms, but it's worth it as an experience.
Inside of a capsule
Tokyo Kiba Hotel