People bang on about capsule hotels being a Japanese revolution of quirkiness and efficiency. To be honest they're just a crappy version of a bunkbed, but they can be handy when you need a cheap place to stay in the business district.
Beware: Height Resitrictions.
カプセルホテル(capuseru hoteru) are pretty common in the bigger cities, and are almost always catered towards business workers who are too drunk to get home or working too late for trains. They will sometimes have a 24 hour onsen as part of the fee, and will almost always have alcohol, cigarette and food vending machines. They're easy to spot by generally having photos of capsules outside in the same way that internet cafes have pictures of the "beds" they offer.
Their reputation for being quirky is not really deserved. Apart from the concept of sleeping in front-loading bunkbeds there's not really anything new here, except that the capsules are usually made of plastic and have a TV, radio and alarm-clock fitted inside. Invariably the TV will have several porn channels, and if you're lucky (like I have been) you can hear other customers enjoying theirs throughout the night.
Those with claustrophobia issues needn't worry unless it's very severe, as there's usually enough room to sort-of sit-up inside. The standard size is 1 metre x 1 metre x 2 metres. This can be a probelm for taller people, however. I'm 6'4" and have a problem with the privacy shutters on some capsules which you pull down in front of the entrance, and closing this means that I can't lie completely flat comfortably and have to do a feotus impression all night (or leave the shutter partly open).
- These will vary from 2,500 to 4,500yen depending on the location and amenities. Many places in the business districts will offer a point system or pre-paid option (pay for nine nights and get the tenth free). Booking ahead is not usually necessary.
- Women are not usually allowed in business capsules, but the more tourist-orientated ones will usually have a women's room, or mixed section at the very least.
- Some capsule hotels offer rooms of four+ capsules for private hire. Capsule Inn Akihabara is an example of this.
- In Akebonobashi (Shinjuku) there is a gaijin-targeted capsule hotel with larger-sized wooden units (~3,500yen). It gets very hot and can be pretty noisy in the mornings, however. They also offer budget beds (although you must request them specifically) for around 2000yen.
- In Kyoto there is a place called Kyoto Ryoukan Capsule, which is a curious cross between a traditional Japanese hotel and a capsule place (3,500yen). The capsules have tatami floors and futons, and the place has a traditional setup. There are also standard ryoukan rooms.