The Immigration Bureau in Nagoya granted special residency status Tuesday to a Thai woman and her daughter residing in Tokai, Aichi Prefecture, because of a serious illness the mother has.
Permission was granted 21 days after the 24-year-old mother applied for residency with the bureau in late March, bureau officials said.
The names of the woman and her 5-year-old daughter and the nature of the woman's disease have not been released.
The woman arrived in Japan in 1991 on another person's passport. According to sources close to the woman, she worked in a restaurant and in other places in Nagoya.
She moved in with a Japanese man and gave birth to their daughter in 1995, the sources said.
When her daughter was born, the mother learned she was chronically ill but unable to join the national health program because she was an illegal alien.
Unable to pay more than 100,000 yen per month for medical fees, she was forced to abandon hospital treatment, the sources said.
In February, her illness worsened, forcing her to undergo full-scale medical treatment.
She decided to file for residency but had insufficient identification for the application, the sources said.
With help from hospital staff and volunteers, the woman eventually obtained the necessary documents from Thailand to process her residency application while she remained in Japan.
She plans to marry the Japanese father of her daughter.