Like most cultures, Japan has certain numbers that are preferred and other numbers that are assiduously avoided. They can divided into two broad classes.

kissû — lucky numbers. Coming from Esoteric Buddhism odd numbers are generally considered auspicious. For instance, the number of incense sticks burnred to the ancestors must always be odd.

1 — Representing the obvious, leadership and importance.

3 — Three things are combined to create harmony and safety such as the sanshu no jingi — the Three Sacred Treasures (Mirror, Sword and Jewels); three sacred emblems of sovereign rule; the three divine symbols of the Japanese imperial throne. In a shintô wedding, there are 3 sips x 3 cups of sake to seal the bond as a married couple

5 — Many cultural ideas use the number 5 such as goshiki — Five colors, go gyô shi shisô — Five Elements, go hôi — Five Directions, and go kan — Five senses.

7 — Many cultural ideas also use the number 7 such as shichifukujin — Seven Luck Deities, the Seven herbs of the New Year, the Seventh day after birth, and the Seventh day after death.

8 — 八 the kanji for Eight is seen as good luck spreading. This is one of the few even numbers considered lucky.

11 — A reference to the self. It symbolizes new beginnings, or the ability to let go and move forward.

kyôsû — unlucky numbers. These are numbers that are often omitted in floors and room numbers in hotels and hospitals, gates at airports and train stations, or are indirectly referenced in every day conversations.

4 — shi can be read as death. Will instead be pronounced as yon,

6 — (mutsu) sounds like mu — nothingness.

9 — ku can be read as hardship. One of the few odd numbers.It has some lucky connotations.

19 — (jûkyu) sounds like jukyu — heavy suffering.

42 — (yonjû ni) can be read as shini — death.

49 — Combines the two most unlucky numbers 4 & 9.

96 — (kujû roku) can be read as kurô — hardship