Pay TV system of Japanese hotels is quite unique. In Europe, you have to confirm the Pay TV channel by the remote controller and you have to pay it when you check out but many Japanese hotels, especially three stars category request the guests to buy a card in advance.
There are multiple digits written on the back of the plastic card and you have to enter the digits when you want to view the pay TV channel. Then, the card is not sold at the reception but there are vending machines located on the elevator halls or at the corridors.
These machines usually accept 1000 yen bill only and there is no button. Just insert the bill and automatically the card comes out.
Genre of the pay TV programs are depended on the hotel but main program is porn. However Japanese try to avoid using a word porn, "Adult" is used instead of porn. Therefore if you hear or see Adult video, it is porn video. AV means Adult video = Porn video. AV actress = Porn actress.