John Key was due to touch down in Tokyo last night and whether he likes it or not, his will be a grand entrance to Japan.

The giant rugby ball promoting the 2011 Rugby World Cup that screams "look at me!" went up at the base of the Tokyo Tower at the weekend.

Tokyo is its third outing after stints sitting at the base of the Eiffel Tower and Tower Bridge in London.

Mr Key will be calling on Emperor Akihito today, and will be holding talks with new Prime Minister Yukio Hatoyama tomorrow.

But the ball will play a central role in Mr Key's week. He and his wife, Bronagh, will be making several visits to it, to officially "open it" today with Japan's rugby coach John Kirwan, to hold a reception in it on Friday for the Japan-New Zealand Partnership Forum, and to host a breakfast in it on Saturday - the morning that the All Blacks and Wallabies contest the Bledisloe Cup in Tokyo.

Rugby and promotion of New Zealand interests in Japan have become closely linked. It is also a convenient fit for Foreign Minister Murray McCully who is also Minister for the Rugby World Cup and is in Tokyo, too.

The timing is part of the New Zealand plan of engagement, Mr McCully explained.

"We have timetabled the visit by the giant rugby ball and the business activity around it to try and give us a strong platform to engage with the Administration in Japan and we couldn't be happier with the level of engagement we have been able to achieve so far," he told the Herald before arriving in Tokyo.

"While Japan is not one of the world-leading nations in rugby in a conventional sense, a large number of their corporate leaders and politicians have had contact with rugby either through playing or involvement with corporate rugby teams in the Japanese competition. Throughout the Japanese system, there are movers and shakers who have an enthusiasm for rugby that makes it a very strong connection with this country."

Former Prime Minister Yoshiro Mori was a good example. He is now president of the Japan Rugby Football Union and Mr McCully will be having talks with him while he is there.

While the rugby ties have been strengthening, however, attention to the diplomatic relationship has been slipping.

After Mr Mori's resignation as Prime Minister in 2001, he was replaced by Junichiro Koizumi who held office for five years. Mr Koizumi was the last Japanese Prime Minister to visit New Zealand, in 2002.

Even more pronounced is that New Zealand received not a single visit from a Japanese Foreign Minister in the nine years of the Labour-led Government. In the same period 16 New Zealand ministers visited Japan.