Participants in Tokyo took part in a sleep competition organised by mattress company Koala, with contestants lying in beds while devices monitored their sleep.
Footage shows them sleeping, moving in their beds and being gently woken by staff before the results are announced.
The competition offered a 2 million yen ($14,000) prize to the winner. Participants said the event gave them a chance to get quality sleep despite busy daily lives. One contestant said she planned to use the money to help pay for moving costs and buy a new bed.
The event also aimed to draw attention to sleep deprivation in Japan. Organisers said the country has a culture of working hard and following the habits of others, which can leave little time for rest.
By turning sleep into a competition, they hoped to encourage people to think more about the importance of getting enough sleep.
