Man breaks into Little Caesars, starts making and selling pizzas, NC police say
(www.charlotteobserver.com)
Commercial rent is hilariously cheap in Japan. So a lot of people will start a business as a hobby, and the business breaks even in those few hours its open.
Then there's people who just run a kitchen/shop right out of their home.
The bar in question is in a 3 story building, with the botton 2 floors for customers, so I don't think the guy even lives there.
Theres a lot of foreigners who do something similar just for visa purposes; you run a "business" selling a parking spot or something to a neighbors or bento or w/e, and have an "office" that's a desk in a shed, and congrats on the business visa.