Azali Assoumani, the president of the Comoros, which is made up of just three islands off south-eastern Africa, has arrived in Hiroshima for the G7 summit.
The Comoros was invited as it is chairing the African Union this year. Normally South Africa attends the summit but Japan has sidelined it for not imposing sanctions against Russia afrer it invaded Ukraine.
This week’s summit of the Group of Seven wealthy democracies includes eight other guest nations: South Korea, Australia, India, Brazil, Vietnam, Indonesia and the Cook Islands.
The Cook Islands was invited as its chair the Pacific Islands Forum and Indonesia chairs the Association of Southeast Asian Nations.
India is due to become the third biggest economy by 2030 and is already the world's most populous, having overtaken China earlier this year.
South Korea is a major Asian economy and a neighbour to host Japan.
Vietnam meanwhile is a close trading partner with China but it's become cautious of its giant neighbour after Beijing reignited a maritime dispute with it.
Countering China is perhaps the biggest task facing the G7.
Then there's the war in Ukraine and the desire to involve other countries in sanctioning Russia for invading Ukraine for the second time.
That explains why the surprise guest to the party was Ukraine's president Volodymr Zelenskyy.
The group is made up of seven wealthy democracies including the US, Canada, the UK, France, Germany, Italy and Japan and the EU also attends.
The invitations to leaders outside the G7 are meant to extend cooperation to a broader range of countries.