expression
sleep four hours and pass, sleep five hours and fail
A set phrase from the era of intense university entrance exam cramming, meaning that sleeping only four hours leads to success while five hours of sleep leads to failure. Used to emphasize the extreme study ethic expected of exam candidates.
受験生の間では「四当五落」という言葉がよく使われていた。
Among exam candidates, the phrase 'four-pass, five-fail' was often used.
「四当五落」の精神で、彼は睡眠時間を削って勉強した。
With the 'four-pass, five-fail' mindset, he cut down on sleep to study.
A coined phrase from the post-war period of intense university entrance exam competition in Japan, combining the numbers 四 (four) and 五 (five) with 当 (hit, success) and 落 (fall, failure).