The hotel, which has hosted many famous guests, began operations in May 1962 but was closed in August 2015 to undergo extensive renovations, Efe news reported.
Elements of the original hotel have been preserved in the main lobby to provide a glimpse of Japanese modernist design.
The lobby was designed by architect Yoshiro Taniguchi and his son, 81-year-old Yoshio Taniguchi, was a member of the renovation team to keep the original spirit intact.
In keeping with the past, the renovated lobby retains its distinctive ceiling lights known as "Okura Lanterns", lacquered tables and chairs arranged like the petals of plum tree blossoms, and a world map-clock.
Hotel Okura has been an integral part of Japan's recent history. In October 1962, a few months after opening, then-Emperor Hirohito hosted a banquet in honour of Mexican President Adolfo Lopez Mateos.
It has also hosted former US Presidents such as Gerald Ford, Jimmy Carter, Ronald Reagan, Bill Clinton and Barack Obama, as well as Russian leaders including Boris Yeltsin and Mikhail Gorbachev.
Other famous guests have been former Beatles member John Lennon, Prince Rainier III of Monaco and his wife Grace Kelly, as well as Prince Charles of England and the late Princess Diana.
The complex will consist of two buildings, one comprising 17 floors and the other of 41, with a total of 508 rooms and office spaces.
( With inputs from IANS )