Beliefs about numbers in Japan : Between superstition and symbolism

In Japanese culture, numbers are not just simple tools for measurement or calculation. They carry deep meanings, sometimes positive, sometimes unsettling. Whether it is about luck, curses, or Buddhist symbolism, numbers influence the daily lives of Japanese people far beyond mathematics. From choosing dates for weddings to numbering hotel rooms, and including funeral practices, this numerical symbolism permeates many spheres of life. Let’s discover together how these beliefs shape habits, traditions, and even the architecture of modern Japan.

The numbers of bad luck in Japan

The number 4: symbol of death

The number 4 is undoubtedly the most feared in Japan. The reason is simple: the word “four” is pronounced “shi” (し), a direct homophone of the word “death” (死). This sound play is enough to provoke a widespread aversion to this number.

In hospitals, hotels, or modern buildings, it is not uncommon for the fourth floor to simply be absent, replaced by “3A” or “5”. Similarly, gifts should never be given in fours, as this is considered to bring bad luck. One also avoids license plates containing a 4, or numbered seats 4 on express trains or airplanes. In the business world, companies show the same caution: omitting this number is a way to avoid a bad omen.

The number 9: pain and suffering

The 9 is also viewed negatively, as its alternative reading “ku” (く) evokes suffering, pain, or agony (苦). This connotation of pain is deeply rooted in the collective imagination. That is why the number 9 is often avoided in maternity wards, hospitals, or during important ceremonies like weddings.

Giving an object in nine copies would be perceived as very bad taste, especially during happy events. Even in universities or large companies, it is avoided to assign lockers or rooms containing this number. The avoidance of 9, just like that of 4, is an expression of a desire for social harmony and respect for traditional sensitivities.

Lucky numbers

The number 7: spirituality and luck

Conversely, the number 7 is very well perceived. It is associated with luck, Buddhist spirituality, and prosperity. This symbolism can also be found in several cultural elements:

The 7 deities of happiness (Shichifukujin), often represented on boats during the New Year
The seventh day after a death, a key moment in Buddhist funeral rites, marks an important spiritual milestone
July 7 is also the day of the star festival (Tanabata), a romantic celebration inspired by a Chinese legend

The number 7 is therefore reassuring and conducive to good energies. It is often chosen in phone numbers, addresses, or product names to bring good luck. Families also prefer dates that include a 7 for important celebrations, reinforcing its positive aura.

The number 8: abundance and growth

The 8 (hachi) is another very favorable number. Its shape evokes an opening, an expansion, and its soft pronunciation is perceived as harmonious. In Chinese culture, which is very influential in Japan, the 8 is synonymous with prosperity, which has been adopted in some Japanese usages:

Many brand names, license plates, or phone numbers incorporate the number 8 to attract success
Harvest or transition festivals often include the number 8 in their calendar
The kanji character for 8 (八) opens downward, symbolizing continuous expansion and thus, growing prosperity

Some Japanese temples even offer rituals related to this number, such as ringing the bell or shrine tours repeated eight times to invoke wealth. The number 8 is not just a lucky charm: it also embodies an optimistic vision of the future.

The impact of these beliefs in daily Japanese life

Architecture, hospitality, and numbering

It is not uncommon in Japan to find that certain floors are “skipped” in elevators, particularly floors 4, 9, or 49, which combine the two unlucky numbers. These absences are not technical errors but deliberate choices based on superstition. Large hotels, hospitals, and even some residential buildings adapt their numbering to avoid discomfort for clients or residents.

In hospitals, rooms numbered 4 or 9 are often modified, avoided, or replaced. This phenomenon is also found in airplanes, high-speed trains, and even in the numbering of seats at shows. Real estate developers go so far as to value apartments with 7s or 8s, often sold at a higher price for their “lucky” potential.

Gifts and offering numbers

The gifts, especially during weddings or funerals, must always be offered in symbolic quantities. Superstition concerns not only the number of items but also the symbolism that the number conveys:

Avoid 4 or 9 items
Favor 1, 3, 5, 7, or 8, often considered positive
In funerals, offering money (kōden) in amounts that exclude 4 or 9 is imperative

Even the bundles of money offered in condolence or wedding envelopes are counted to avoid “unlucky” numbers. Souvenir shops, kimono stores, or tea shops often adapt their sales lots to these norms to avoid offending Japanese sensibilities.

Numbers and Japanese spirituality

The role of numbers in Buddhism

In the Buddhist tradition of Japan, certain numbers hold great spiritual significance:

108 : number of human desires according to Buddhism, which one seeks to purify during the transition to the new year by ringing the temple bells (Joya no kane). This ritual, very popular, is a form of symbolic purification before entering a new year.
6 : the six realms of reincarnation in Buddhist cosmology, which explain the cycle of rebirths (rokudō)
3 : reference to the three jewels (Buddha, Dharma, Sangha), fundamental pillars of the Buddhist faith

These sacred numbers influence many religious practices, funeral rituals, and seasonal events. They are not only religious but also rooted in everyday objects like sutras, household altars, or Buddhist calendars.

Amulets and lucky objects with numbers

Certain objects sold in temples or traditional shops feature symbolic numbers. For example:

Some omamori marked with the number 7 or 8 for luck
Sets of bells sold in 5 or 7 units to ensure the protection of homes
Incense offered in packs of 108, to echo the human desires to purify

These spiritual objects combine aesthetics and numerical symbolism. They embody a form of cultural continuity, where each number evokes a wish, an intention, or a specific blessing. Even in tourist shops, these numbers are highlighted to attract visitors curious to discover a part of Japanese spirituality.

Why do these beliefs still persist today?

Modern Japan, even ultra-technological, remains deeply rooted in its symbolic culture. Young generations, even when they do not literally believe in superstitions, still respect the codes, especially in social relationships, gifts, or family rituals. This respect for conventions is not seen as a constraint, but rather as a form of politeness and collective harmony.

These beliefs are transmitted without being imposed: they are integrated into daily life in a discreet but persistent manner. They reflect a culture where signs, sounds, and shapes always have meaning. They are not questioned: they are there to preserve balance, avoid misunderstandings, and create continuity between generations.

The maintenance of these practices is also reinforced by the media, literature, Japanese horror films (where the number 4 appears frequently), and year-end traditions. Far from being a simple outdated superstition, the symbolism of numbers continues to shape contemporary Japanese culture.