Japanese Emperor Akihito will be called "emperor emeritus" and Empress Michiko "empress emerita" following his abdication in April, the Imperial Household Agency said Monday.

Their Japanese titles to be used after the abdication have already been decided as "joko" and "jokogo," respectively. The agency came up with the English titles through consultation with the Foreign Ministry after studying those used by overseas royal families.

The agency said the word "emeritus" is used to express admiration and respect for the accumulation of experiences and achievements and "suitable to refer to the joko who commands great respect after abdication."

The 85-year-old emperor will abdicate on April 30, becoming the first living monarch in Japan to do so in about two centuries, and will be succeeded by his eldest son Crown Prince Naruhito, 59, on May 1.

After the crown prince ascends the Chrysanthemum Throne, his younger brother Prince Fumihito, 53, will be first in line to the throne and called "koshi" in Japanese and crown prince in English, according to the agency.