“There are even people who say they will pay 20,000 or 30,000 yen ($130-190) a month (if they can) live here forever,” said Takayoshi Shiranaga, an officer at Tochigi Women’s Prison located north of Tokyo, during an extremely rare visit granted to CNN in September.

The women in Tochigi live behind bars and must work in the prison’s factories, but that suits some just fine.

Inside they get regular meals, free healthcare and eldercare – along with the companionship they lack on the outside.

“(Some people) do bad things on purpose and get caught so that they can come to prison again, if they run out of money,” said Yoko, who CNN is identifying by a pseudonym for privacy reasons.