But as it turns out, if the Prime Minister had gone earlier she would have missed meeting the high-profile Japanese parliamentarian Shinjiro Koizumi, who has been visiting New Zealand as the 2018 Prime Minister's fellow.
Koizumi is the second son of former Prime Minister Junichirō Koizumi who served as Japan's leader from 2001-2006. He has been the Chief Deputy Secretary General of the ruling Liberal Democratic Party (LDP) since August 2017.
Interestingly Koizumi is the same age as Ardern, speaks perfect English, and is charismatic and popular with the Japanese public.
Talking with him informally yesterday he appeared to be very impressed by our own youthful Prime Minister. Not only was she a Prime Minister at his age, but also a mother who was "partnered" not married. This speaks to the social change that many younger people in Japan would like to occur.
Koizumi is seen as a future leader. He wants to see nuclear power phased out over time and is interested in New Zealand's profile of renewable energy. More importantly he is promoting a new partnership between New Zealand and Japan.
The two countries not only share a democratic tradition but have respect for human rights and nature, and the rules-based international order. This is important in an increasingly complex region.
With the CPTPP deal expected to go into force next year this growing interest in reenergising the bilateral relationship holds strong promise.
Not just politically but also on the economic front when it comes to areas like investment in forestry to name just one potential pathway.
He has been accompanied by two other parliamentarians who are also children of former prime ministers.
Yuko Obuchi, daughter of former Prime Minister Keizo Obuchi, who was the first serving cabinet minister in Japan to give birth while in office in 2009 and briefly served as Minister of Economy, Trade and Industry in 2014. And Tatsuo Fukuda the Parliamentary Vice Minister of Defence, whose father is former Prime Minister Yasuo Fukuda (2007-8) and whose grandfather, Takeo Fukuda, was Prime Minister from 1976-78. Takashi Yamashita, the Parliamentary Vice Minister of Justice, rounded up the delegation.
The visit comes on top of a recent visit by the Japanese Deputy Prime Minister and Finance Minister Tarō Asō, and Vice Minister of Finance for International Affairs, Masatsugu Asakawa, who were hosted by Peters at his Auckland home.
Japan is the world's third largest economy, New Zealand's fourth largest trading partner, and a source of high-quality foreign investment.
But Japan's positioning here has slipped somewhat in the time since New Zealand forged an FTA with China. Both Japan and New Zealand are seeking to balance China's growing weight in the region.
Like other Pacific Partners, who the NZ foreign minister has been lobbying, Japan is expected to strengthen the co-operation with New Zealand in the delivery of our respective development assistance programmes in the Pacific.
Staying back for the Koizumi visit was money well spent.