Love Hotels are everywhere in Japan. They're big business. On any one day — 6 million people stay at one (that's 5% of the Japanese population).
Love hotels are short stay hotels where you can stay anonymously and pay cash. Many Westerners assume these are the haunts of illicit affairs (and to some extent that is true). However, love hotels are used by normal couples. Married couples use them. They're not always as seedy as you might imagine.
Love hotels aren't difficult to find. They're often found in entertainment districts or near highway interchanges. Many of the nicest love hotels are in the suburbs.
Love hotels are designed from the ground up for discretion with entrances hidden from public eyes.
There are usually plans to stay from 3 to 10 hours depending on the time of day. A short stay is called "rest" and a longer period is called "stay".
Only male-female couples (and groups of females) can stay at love hotels and there are no come-and-go privileges on the room.
To rent a room go to the lobby and there will be photos of all the rooms with buttons. The rooms that are available will be lit up. Select the room you want by pressing the corresponding button and pay the woman behind the desk in cash. Be careful to make clear what time you must leave there is usually a high penalty for overstaying (they usually call you ten minutes before your time is up).
Love hotel rooms are often imaginatively themed and have large beds and nice bathrooms. They sometimes feature entertainment such as Karaoke machines and video games. Love hotels tend to be reasonably priced as compared with regular hotel rooms.