I am familiar with the japanese capsule hotels, and thankfully no one ever went nuts and made something even smaller and creepier (as far as I know…). Instead some germans made something kind of similar. Hotel rooms out of drain pipes. It’s pretty cool actually.
“It is constructed from repurposed, incredibly robust drain pipes. The external simplicity surrounds an unexpectedly comfortable interior – full headroom, double bed, storage, light, power, woolly blanket and light cotton sleeping bag. All other hotelery devices (Toilets, showers, minibar, cafe, etc) are supplied by the surrounding public space.”
The hotel website: http://www.dasparkhotel.net/parkhotel/index.php