Japan's global superstar Naomi Osaka on Friday lit the Olympic cauldron to mark the start of Tokyo 2020, in an opening ceremony shorn of glitz and overshadowed by a pandemic but defined by hope, tradition and gestures of diversity.

Postponed by a year due to the coronavirus, the Games are being held without spectators in a city under a Covid-induced state of emergency, as many other parts of the globe also still struggle with a resurgence of cases.