Japan’s Princess Ayako has married a commoner in a ritual-filled ceremony in Tokyo.

Ayako and groom Kei Moriya were shown on Monday’s national news walking slowly before guests at the capital’s Meiji Shrine.

The wedding took place in one of the pagoda-like buildings in the shrine complex and included an exchange of rings and a sharing of a cup of sake, according to Japanese media.

Both rituals are relatively routine for Shinto-style weddings, including those of regular Japanese.

Japan Royal Wedding
Japanese Princess Ayako and Japanese businessman Kei Moriya arrive at the Meiji Shrine for their wedding ceremony (AP)

Ayako, 28, is the daughter of the emperor’s cousin, and Mr Moriya, 32, works for major shipping company Nippon Yusen.

She wore a Heian-era style hairdo, which is swept back into a ponytail, and a traditional robe splashed with red and green patterns, while Mr Moriya wore coattails.

She later changed into a red Japanese robe.

“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.

Mr 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.

Japan Royal Wedding
Japanese Princess Ayako, leaves her residence before her wedding (Kyodo News/PA)

She said 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.

Japan Royal Wedding
Japanese Princess Ayako, dressed in a traditional ceremonial robe, and groom Kei Moriya visit Meiji Shrine (Kyodo News/AP)

His eldest son, Crown Prince Naruhito, will ascend to the Chrysanthemum Throne on May 1.

Ayako and Mr 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.

Mr 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 football, died in 2002.