The Imperial Household Agency said Monday it will officially announce the engagement of Princess Mako, the first granddaughter of Emperor Akihito, to a university classmate of hers on July 8.

Following agency chief Shinichiro Yamamoto's announcement, Princess Mako, 25, and her fiance-to-be, 25-year-old Kei Komuro, will hold a news conference together the same day, the agency said.

The agency has selected the day, which falls on Saturday, in light of possible impact on Komuro's work. He currently works as a paralegal at a law firm in Tokyo and attends Hitotsubashi University's graduate school.

The couple are expected to marry sometime next year, according to agency sources.

Komuro was a classmate of the princess while they were attending International Christian University in a Tokyo suburb.

They met about five years ago through a mutual friend and soon started going out, before Komuro proposed about a year later, according to a source close to the matter.

The upcoming engagement of the elder daughter of Prince Akishino and Princess Kiko will be the first among the four grandchildren of the emperor and Empress Michiko.

The news of their impending engagement broke in mid-May, weeks before legislation aimed at enabling the 83-year-old emperor to abdicate and pass the throne to Crown Prince Naruhito was enacted on June 9.

The news has shed light on the urgent need to address the issue of the dwindling size of Japan's imperial family as princesses cannot become reigning empresses and will have to leave the family upon their marriage to commoners under the current law.

The envisioned engagement is expected to reduce the number of the imperial family to 18, including the emperor himself.