.In Japan, the numbers four (shi, also the word for death) and nine (ku, rhymes with kutsuu which means “pain”) are considered unlucky.
As a result, some buildings in Japan don’t have fourth or ninth floors.
On the other hand, the number seven is considered lucky in Japan. Japanese Buddhists celebrate a baby’s seventh day of life, the Shichifukujin are the Seven Gods of Luck, and Japanese people celebrate Tanabata, (the Evening of the Seventh) each summer on July 7th.