"I am filled with happiness," she told reporters after the ceremony.

Women who marry into the imperial family become members of the family, but those who marry commoners, like Ayako, must leave.

Moriya said he hoped to help Ayako adjust to a commoner's life.

"I want us to work together, hand in hand, to create a family filled with smiles," he said.

Ayako bid farewell to Emperor Akihito last week. She said Monday she hoped to continue to help the emperor and empress as a former member of the imperial family.

The eldest granddaughter of the emperor is set to marry a commoner in 2020.

Akihito has said he will abdicate next year. His eldest son, Crown Prince Naruhito, will ascend to the Chrysanthemum Throne on May 1.

Ayako and Moriya said when they announced their wedding plans that they met because their mothers were friends and hit it off immediately.

"It didn't feel as though we had met for the first time," Ayako told reporters at their engagement.

Moriya said he had been attracted to her gentle spirit.

"And I knew I wanted to spend the rest of my life with her," he said.

Ayako's father, Prince Takamado, who was active in supporting Japanese soccer, died in 2002.

AP