Oyasumi Stray Sheep

Japan is the country with the shortest sleep time in the world. Despite being born in such a sleep-deprived country, Shinya Moroboshi is an unemployed man who sleeps a lot and lives a self-indulgent life that has nothing to do with lack of sleep. One day, Moroboshi finds an unfamiliar "sleep selling app" on his phone. He uses it with some skepticism, but to his surprise, he is able to actually sell his sleep and make money...!? (Source: Comic Zenon, translated)