“Congratulations,” replied Masaki Koh, a Japanese gay porn star. “Your wonderful wedding will bring inspiration and hope to many people who still hesitate to take the first step. I was also encouraged that Tokyo Disney Resort was so understanding.”

But on the Naver Matome site, which collects and curates social media entries, a user who identified himself as Nizo Hakoda remarked: “I don’t particularly mind homosexuality and same-sex marriage, but watching the news made me wonder why they had to hold their ceremony at a crowded place like Disney. It’s fine for the people who accept it, but there are others who don’t.”

The Walt Disney Company had long allowed same-sex celebrations in a limited way on its grounds, like in banquet halls. But in 2007, it began allowing same-sex couples to buy high-end wedding packages, which can include elaborate ceremonies, Disney characters and public displays at its theme parks and on its cruises.

Despite that change in policy, Ms. Higashi found that no same-sex wedding had ever occurred at Tokyo Disney Resort. She reported on her blog and on Twitter that she had inquired about weddings at Tokyo Disney Sea, a part of the Disney Resort. But when it became apparent to the organizers that her partner was female, Ms. Higashi reported, she was asked if one of them could wear a tuxedo — so that other visitors to the park would not feel uncomfortable.

Her posts set off the first stir on Japanese social media sites.

A week later, the organizers at Milial Resort Hotels, a subsidiary of the company that runs Tokyo Disney, got back to Ms. Higashi with good news: both brides were welcome to wear wedding dresses (or both tuxedos, for that matter). “Mickey Mouse supports gay marriage!” Web headlines declared.