They didn't want to copy the capsule hotels popular in Japan, which are used mainly to bunk in for a night.

FORBES: Magazine Article

The most miniscule quarters by far are found in the slew of capsule hotels found throughout Tokyo and the rest of Japan.

FORBES: The World's Tiniest Hotel Rooms

The concept can be traced to Japanese capsule hotels, first developed around 1980, and appeal to travellers looking to nod off or work in private without having to pay for a traditional hotel room or leave the airport.

BBC: Sleep in a pod on the fly