TOKYO, May 27 (Yonhap) -- The upper house in the Japanese Diet on Friday ratified an agreement on the return of ancient Korean texts to Seoul, completing a legal process for the transfer considered key to improving bilateral relations.

   The House of Councillors in Tokyo approved the ratification bill on a 145-86 vote, about a month after the House of Representatives, the lower house, passed the bill. It is expected to take effect next Tuesday, following a Cabinet meeting.

   Last November, Japan agreed to return a total of 1,205 volumes of archives that were seized during its 1910-45 colonial rule of Korea, including texts of royal protocols known as "Uigwe."

   The deal represented Tokyo's first concrete step forward after Prime Minister Naoto Kan in August pledged to return the books and other Korean cultural relics as a show of goodwill. Japan is to return the texts within six months after the deal takes effect.

   The main opposition Liberal Democratic Party (LDP) voiced some opposition, saying Kan hastily reached the agreement without demanding Korea's return of Japanese books or considering other alternatives, but it didn't win much support in the house.

   The April passage in the lower house had virtually completed the process. If a treaty between Japan and another country is ratified by the lower house, it would go into effect after 30 days, regardless of the decision at the upper house.

   Uigwe is a collection of documents from the Joseon Dynasty

(1392-1910) containing details on procedures and formalities conducted for weddings, funerals, banquets and receiving foreign missions as well as cultural activities of the royal family.

   Japan is believed to be holding 167 Uigwe books, including 81 originals, at its Imperial Household Agency, after the books were looted from a Buddhist temple in 1922. South Korea has 3,563 Uigwe books, 703 of them originals.

(Yonhap News)