Abstain From Using The Number Four, Trust Us
This one is tricky, especially if you are a native English speaker. For you see, the number “four” is avoided at all costs in Japan because it sounds almost the same as the word for death. As such, the number “four” is seen as an unlucky number like the number “thirteen” is in Western cultures.
You are not to even give other people anything in fours, as this is also seen as a bad omen. Do not be surprised if you visit the country and find yourself not having a fourth-floor option. It should go right to the fifth floor. The practice of avoiding the number “four” is called “Tetraphobia,” and enjoys strict enforcement.