Japan's royal couple are returning to India more than half a century after their last visit.
The 79-year-old Emperor Akihito was crown prince when he and his wife travelled there in 1960.
"I hope our visit will contribute to further enhancing the understanding and friendship between the two countries which marked the 60th anniversary of diplomatic relations (last year)," Emperor Akihito said at Tokyo's Haneda Airport.
During their week-long visit, Emperor Akihito and Empress Michiko will meet Prime Minister Manmohan Singh and other top officials in New Delhi before flying to the southern city of Chennai.
In a message released earlier this week, the emperor remembered his last trip to India, one year after his marriage.
"I still recall fondly how Their Excellencies President Rajendra Prasad, Vice President Sarvepalli Radhakrishnan, and Prime Minister Jawaharlal Nehru welcomed us most graciously in Delhi," he said.
"I feel it was profoundly meaningful for us to have had the opportunity to meet with these great leaders when we were young. We were still in our mid-twenties then," Emperor Akihito added.
Japan's emperor is the nominal head of state and does not enjoy political powers.
But customarily, the emperor's visit to any country is highly significant and signals a peak in bilateral ties.