On May 12, 2012, the Imperial Household Agency released a statement from His Imperial Majesty Emperor Akihito of Japan regarding Her Majesty Queen Elizabeth II and the Diamond Jubilee celebrations:
It is with great pleasure that together with the Empress I will visit the United Kingdom to attend a luncheon in commemoration of the Diamond Jubilee of Her Majesty Queen Elizabeth II, to which she has invited monarchs of various countries. I would like to express my deepest gratitude to Her Majesty for this invitation.
The Coronation of Her Majesty Queen Elizabeth II was held soon after World War II, in June 1953, the year after the Treaty of Peace with Japan went into effect. At that time, being 19 years old, I attended the ceremony representing Emperor Showa, and taking that opportunity, visited quite a few countries in Europe and North America, a trip during which I learned and experienced so much.
To read the statement in its entirety please click here. (in English)
Source: The Mainichi via the Imperial Household Agency Press Release.