In the run-up to this year's Tokyo Olympics, this edition of Witness History is presented from Japan and introduces us to five important moments in Japan's history:

1) The introduction of the Shinkansen, or bullet train between Tokyo and Osaka.
2) The campaign to make the contraceptive pill available in Japan.
3) The trees that survived the atomic bombing.
4) Industrial waste poisoning.
5) The royal wedding that broke over 2,600 years of tradition.