G7 - the "Group of Seven" countries - came together in 1975 as the seven most important industrialized nations at the time.
These seven countries are the US, the UK, France, Germany, Italy, Japan and Canada. In 1998 Russia was added and the group expanded to G8, before it was excluded again in 2014 after Russia's annexation of the Crimean peninsula.
There's much to discuss at the G7 summit in Japan, as worldwide crises mount and tensions with Russia and China heighten. DW's Michaela Küfner says the leaders are going to have to do more than just smile for the camera.
John Kerry has become the highest-ranking US official to visit the memorial to victims of the Hiroshima bombing. At a meeting in the city, G7 foreign ministers agreed to push for a "world without nuclear weapons."