Princess Ayako and Kei Moriya after their wedding ceremony. Photograph:( Instagram )
The couple got married in Tokyo on Monday.
Princess Ayako, the 28-year-old daughter of the emperor's cousin married 32-year-old Kei Moriya on Monday at Tokyo's Meiji Shrine.
The groom, who does not have a royal lineage, works for major shipping company Nippon Yusen. Also see: In pics: Japan's royal wedding
The couple was shown on national news walking slowly before guests at the shrine Monday morning.
She wore a Heian-era style hairdo and a traditional robe splashed with red and green patterns while Moriya wore coattails.
The couple exchanged rings and read out the wedding oath during the Shinto ceremony attended by about 30 people including family members.
Women who marry into the imperial family become members of the family, but those who marry commoners, like Ayako, must leave the family as per law.
The eldest granddaughter of Emperor Akihito is set to marry a commoner in 2020.
Akihito has said he will abdicate. His eldest son, Crown Prince Naruhito, will ascend to the Chrysanthemum Throne on May 1.
(With PTI inputs)