This article discusses the history, reading and writing, common uses, cultural significance, and examples of how to use number 20 in Japanese. It is used when counting items such as books or pieces of clothing, giving someone's age or counting years since an event occurred, expressing time such as minutes or hours past an hour mark, expressing dates such as the twentieth day of a month or year, expressing money amounts such as yen or dollars per unit item sold/bought etc., expressing measurements such as centimeters or millimeters etc., and counting people's birth order within their family. Number 20 has a special cultural significance in Japan due to its association with youthfulness and vigor. Examples are given for how to use it in everyday life.