Mitsutoki Shigeta’s case raised eyebrows in 2014 when police raided a Bangkok property and found nine babies and nine nannies living in unfurnished rooms.
It was determined that Mr Shigeta had fathered the children using Thai surrogate mothers. The case helped usher in a Thai law prohibiting commercial surrogacy for foreign clients.
On Tuesday, Bangkok’s Central Juvenile and Family Court gave Mr Shigeta sole legal custody of the children, saying he had showed plans to care for the children and is financially stable.
It also noted that the children were born before the new law, and that the surrogate mothers had signed documents waiving their custody rights.
Mr Shigeta is the son of an owner of a listed Japanese company and earns over 100 million baht (£2.26 million) in annual dividends, according to the court. It said Mr Shigeta had opened bank accounts in Singapore for all 13 children.
The court said DNA evidence confirmed Mr Shigeta is the children’s’ father. He plans to send the youngsters to an international school and has bought a piece of land to house them next to a large park in central Tokyo, where they will be looked after by a sufficient number of nurses and nannies.
Reports in Thai media in 2014 said he had fathered 16 children in Thailand, but the court’s decision mentioned only 13.
According to the court, Mr Shigeta has taken care of other minors, born from surrogacy, and raised them in Japan and Cambodia, where they were well looked after. The children that he cared for in Japan now all have Japanese citizenship, it said.
It is unclear where the children born in Cambodia are now. Cambodia inherited much of the surrogacy for hire business for foreigners after Thailand banned it, but later passed its own law against it.
The court said Mr Shigeta did not show behaviour linking him to human trafficking, which had been a concern when his story was originally revealed.