For most people, going to watch the Olympics is a once-in-a-lifetime opportunity, but for 92-year-old superfan Naotoshi Yamada it has become a quadrennial ritual over the last five and a half decades.

Yamada, known to his Japanese compatriots as "Olympic ojiisan" ("Olympic Grandad"), first experienced the Summer Games when Tokyo last hosted the gathering in 1964, and he has been there for every minute of every one since.

"Mexico, Munich, Montreal, Los Angeles, Moscow. Japan did not even participate at the Moscow Olympics but I went to see that games," said Yamada, speaking in Tokyo.