A US citizen barred from receiving a long-term visa to see his husband in Japan has sued the country's government, claiming he is being denied a family life.

Andrew High, who met his Japanese husband 15 years ago in the United States and married him there in 2015, legally challenged the Japan government on Wednesday.

He is demanding the same long-term residence rights enjoyed by heterosexual couples in the country.

According to Japanese law, foreign nationals married to Japanese in heterosexual marriages are granted long-term residence status upon arrival in Japan, but those in same-sex marriages are not.

Though nearly two dozen Japanese cities, towns and wards issue certificates recognising same-sex partnerships, they lack legal standing.

The worst destinations for LGBT+ holidaymakers Show all 10 1 /10 The worst destinations for LGBT+ holidaymakers The worst destinations for LGBT+ holidaymakers North Macedonia 16 per cent Getty Images The worst destinations for LGBT+ holidaymakers Moldova 14 per cent Getty Images/iStockphoto The worst destinations for LGBT+ holidaymakers Lichtenstein 14 per cent Getty Images/iStockphoto The worst destinations for LGBT+ holidaymakers Belarus 13 per cent Getty Images/iStockphoto The worst destinations for LGBT+ holidaymakers San Marino 13 per cent Getty Images/iStockphoto The worst destinations for LGBT+ holidaymakers Monaco 11 per cent Getty Images The worst destinations for LGBT+ holidaymakers Russia 10 per cent Getty Images The worst destinations for LGBT+ holidaymakers Armenia 6 per cent Getty Images/iStockphoto The worst destinations for LGBT+ holidaymakers Turkey 5 per cent Getty Images The worst destinations for LGBT+ holidaymakers Azerbaijan 3 per cent Getty Images/iStockphoto

Japan remains deeply conservative and its constitution says marriage is between a man and a woman.

His husband, Kohei, who does not want his last name or occupation revealed, joined him in a separate suit demanding 11 million yen (£83,000) in damages, their lawyer, Masako Suzuki, told Reuters.

"It's violating their constitutional rights and also international conventions, because it's infringement of their right to have a family life," Suzuki said.

The long-term residence status stretches from one to five years. High is on a short-term visa that expires next month.

A former software developer at a US university, High has lived in Japan on and off with Kohei since 2009.

At one point he founded his own company in Japan and gained a "business manager" visa, but lost that visa when the company ran into financial difficulties.

He then applied for a long-term residence visa granted under special circumstances but was rejected five times.

"If they're separated because he has to leave Japan, it's a violation of their right to have a family life," Suzuki said.

"But then if his Japanese husband has to leave Japan so they can live together, it's a violation of his right as a Japanese citizen to live in Japan."

A Justice Ministry official said they had yet to receive full details of the case and could not comment.

Suzuki said she was hopeful because of recent legal cases, including one in March in which a man from Taiwan was allowed to stay with his Japanese partner.

Independent Minds Events: get involved in the news agenda

Last month, a Southeast Asian transgender woman was also granted permission to stay.

Japan's laws on LGBT+ rights are relatively liberal compared with those in many Asian countries, although many LGBT+ people in still conceal their sexuality.

But Japan's conservative ruling Liberal Democratic Party said in its 2016 manifesto that "same-sex marriage is incompatible with the constitution".

On Valentine's Day, 13 same-sex couples filed suits in at least four Japanese cities, saying the government was violating their constitutional rights to equal treatment.