After the Reverend Sun Myung Moon founded the Unification Church in Seoul in 1954, the church was set up in Tokyo in 1959 and was registered 10 years later. But it really took off in Japan after Ms Yamasaki, then 32, and "talento" entertainer Junko Sakurada joined 20,000 others from 131 countries in the church's first mass arranged wedding in South Korea in August 1992.
Ms Sakurada disappeared from public life soon after the ceremony. She is happily married with three children and wants to stay out of the limelight, a church spokesman says. Within seven months of the wedding Ms Yamasaki, too, had disappeared - but without telling her new husband Hideyuki Teshigawara, then 28.
He filed a missing person's notice on March 10, 1993. Police began a 46-day search amid rumours Ms Yamasaki had been kidnapped or run away from the church. Then one morning she appeared at a nationally televised news conference, saying "Everything was a mistake".
"I was placed in a world of delusion where people's minds were being controlled," she said later. "So I still cannot figure out to what extent the affection I felt towards Teshigawara was real."
She has had support. "Only people who have been deeply involved in the activities of the organisation can understand how serious the problem is," a person who knows Ms Yamasaki told The Australian at the weekend. "Outside people will not understand. To persuade the people to get out is extremely difficult. It may take a whole life."
About 40,000 couples from across the world were due to be married in the Seoul ceremony yesterday, but most were already wed and simply reaffirming their vows.
The church spokesman said this mass wedding would not be as important for Japan, "without any talento". Yet 12,000 Japanese Moonies paid their airfares and accommodation on top of a 1.4 million yen ($19,178) donation to the church to participate in a four-day festival that culminated in the ceremony.
The Moonies suffered from Ms Yamasaki's disappearance and a backlash against cult religions following the 1995 sarin gas attack in Tokyo by the Aum Supreme Truth sect. They have been ordered to pay damages to women who were coerced by Moonies into giving donations.
Yet the Unification Church still has 600,000 followers, 8,000 lecturers, 4,000 teachers and 3,600 churches in Japan. Last year it considered a mass wedding for 15,000 people at the Winter Olympics in Nagano, but Games organisers received strong objections. The church, officially known as the Holy Spirit Association for the Unification of World Christianity, chose New York instead.
The church claimed 360 million couples were expected to take part in yesterday's ceremony worldwide via satellite and Internet links, but experts have raised doubts so many people will take part.