In Japanese culture, the number four is feared and fended against because it sounds like death.
The number 40 is unlikely to evoke positive sentiments either, after Japan's Deputy Prime Minister Taro Aso last week declared the Tokyo Olympics a 40-year curse.
Mr Aso made the comment before the International Olympic Committee agreed with Japan on Tuesday to the first Olympic postponement in Games history owing to the global coronavirus pandemic.
He told a parliamentary committee last week: "It's a problem that's happened every 40 years - it's the cursed Olympics, and that's a fact."
The jinx started in 1940, when the Olympics hosting rights were taken from Tokyo and handed to Helsinki before the Games were cancelled altogether against the backdrop of World War II.
Tokyo had been the first non-Western city to win an Olympic bid, but as the war intensified, countries had asked for a different venue and threatened a boycott.
A boycott did materialise - 40 years later.
In 1980, only 80 nations were represented, while 65 countries and territories, including Japan, the United States and China, did not participate in the Moscow Olympics as they protested against the Soviet Union's invasion of Afghanistan.
Japan last hosted the Olympics in 1964. And eagle-eyed netizens have highlighted a key event that happened that year.
Then Japan Prime Minister Hayato Ikeda was diagnosed with laryngeal cancer and announced his resignation after the closing ceremony in Tokyo. He died in 1965.
Interestingly, a scene from 1988 anime Akira had predicted Tokyo would host the Games in 2020 - but a countdown signboard was graffittied with the words, "just cancel it".
As the virus wreaked global havoc in real life, the reel world proved strangely prophetic. While the Olympics will go on, it will have now to wait at least another year.