CHANGSHA /China — The two young men met through an online chat group. They began seeing each other every day. Long walks in the park. Movies and barhopping. Dinner with grandparents.

On their first anniversary, in June, the men, Sun Wenlin and Hu Mingliang, tried to register to marry at a local civil affairs bureau in this southern provincial capital. An employee refused, saying Chinese law did not permit same-sex marriage. The couple did the unthinkable — they sued the civil affairs bureau.

This month a district court accepted their case, the first time a Chinese court had agreed to hear a lawsuit on same-sex marriage. The proceedings had been expected to start Thursday. Some Chinese news organizations have reported on the case, including the English-language edition of Global Times, a prominent state-run publication.

“Whether I want to marry or not, it should be my right to decide,” said Mr. Sun, 27, as he ate dinner at a fish restaurant on Wednesday. “I increasingly wanted to bring this lawsuit because they wouldn’t give me the right.”

Mr. Hu, 37, a security guard, said, “I had relationships before, and I had thought about getting married before. The state wouldn’t allow me, and my family wouldn’t allow me. There were many obstacles.”

Though some local officials have tried to signal their disapproval — two police officers showed up in December to question the couple — the case has galvanized some gay rights advocates in China. This society is still relatively conservative when it comes to sexual relationships, and many gay men and lesbians choose to keep their sexual orientation hidden and marry people of the opposite sex because of parental pressure.

But increasingly, gay men, lesbians, bisexuals and transgender people are asserting their rights, especially as they see more Western nations approving same-sex marriage.

“Before, their voices were unheard, and people did not know such a group of people existed and had needs for marriage,” said Li Yinhe, a sexologist who has pushed for a same-sex marriage law and recently revealed that her longtime partner was a transgender man.

“It’s very brave of the couple to publicly apply for marriage like this,” she added. “Having more people know about the issue will help with both fighting social discrimination and winning approval for same-sex marriage.”

After dinner on Wednesday, the couple strolled hand-in-hand through the neon-lit streets of eastern Changsha, not far from Mao Zedong’s hometown. Mr. Sun, who works in Internet marketing, is the more outspoken of the two, though he has never had a reputation as a gay activist.

For eight months starting in October 2014, he ran a teahouse in southern Changsha where he gave weekly talks on sexuality and identity. “I wanted to have a little home that was diverse and friendly, and gradually have a world that is diverse and friendly,” he said. During the talks, people would sometimes reveal to others for the first time that they were gay.

Mr. Sun told his family he was gay at age 14, when he was asked by a relative at a dinner for his grandmother’s 70th birthday whether he had a girlfriend. “I like boys,” Mr. Sun recalled saying. He said his father kicked him after they got home, and that he punched his father back.

There followed a “cold war” with his family for seven or eight years, Mr. Sun said. While living with his grandparents, he would bring dates home, and his grandparents would cook them dinner and avoid asking questions.

The thaw did not begin until 2014. That Mother’s Day, Mr. Sun and his mother visited an island in Changsha with a famous statue of a young Mao. “I explained to my mother that being gay is a basic human right,” he said. “It’s internationally recognized. My mother accepted the fact that I’m gay. Since then, my mother has stood by me on this matter.”

The next month, Mr. Sun and Mr. Hu messaged in the chat group. They met in person that day and have not been apart since.

Mr. Hu said his mother now approved of his sexuality, and Mr. Sun plans to meet her for the first time over the Lunar New Year holiday next month. (“I’m nervous — I asked my boyfriend yesterday what gift I should get his mother, and he said, ‘I don’t know, either,’ ” Mr. Sun said.)

Getting the lawsuit accepted by the Changsha Furong District People’s Court was not easy. The couple found a lawyer who agreed to take the case but then dropped it after his firm objected. That lawyer recommended Shi Fulong, whom the couple hired and who filed the case in the court on Dec. 16.

A court employee refused to accept the paperwork at first, but Mr. Shi pointed to new regulations passed in May that made it tougher for courts to reject cases without giving a strong reason.

Then, on the night of Dec. 24, two police officers visited the couple at the home of Mr. Sun’s grandparents. The men spoke for 40 minutes. The officers said the court had not sent them. They said a married couple had an important duty to have children. “I said, ‘If you want to reproduce, you go ahead and reproduce,’ ” Mr. Sun said. “If I’m not interested in reproducing, I won’t. Don’t interfere with my rights.”

The couple were told on Jan. 5 that the case had been accepted.“Many people are excited because more gays are speaking up,” said Fan Popo, a gay filmmaker and activist. “Some gay men say they don’t care because they never want to get married. I disagree. I think it’s about equal rights, not about marriage.”

The first hearing was scheduled for Thursday, but the couple’s lawyer heard Tuesday that it had been postponed indefinitely because a lawyer representing the civil affairs bureau was busy, Mr. Sun said.

He added that the judge had called him the same day and said, “The hearing will be the day after tomorrow — are you O.K. with private information becoming public?” Mr. Sun said he was fine with that, and the judge then called Mr. Hu to ask the same thing.

The district court and the local police unit could not be reached for comment on Wednesday.

Mr. Sun said the case had cost them about $1,200 so far, nearly three times what each of them earns in a month. But he said they were determined to see it through to the end.

“Around the world, in other places, gay people have joined forces to fight for their rights,” he said. “They can get married and no longer face discrimination. Inside China, we still live a life like this. We can’t get married and we suffer discrimination.”

He added: “If I hadn’t seen the outside world, then I wouldn’t care. But I have seen the outside world, and I feel terrible. China needs to take bigger steps.”

Source: The Newyork Times