Japan has had a tumultuous, and at times controversial relationship with Mount Everest. Its history features the first woman summiteer, a heated race to claim the crown of oldest person to the top, a disastrous early expedition — and one of the mountain's most infamous casualties.

1963: The first Japanese group gets a climbing permit for Everest, but is thwarted when Nepal closes the Himalayas to mountaineers. The ban is lifted in 1969 and preparations begin anew.

1970: The Japan Mount Everest Expedition 1970 sets off. Costing ¥100 million, the 39-strong team, plus 21 Sherpas, 30 Icefall porters and 30 staff at Base Camp, it is one of the largest expeditions ever mounted, but is beset by tragedy.