To the Japanese, the bow is something they do every day. Children bow to their teacher and say "ohayou gozaimasu," or "good morning," at the start of every school day. It would be unthinkable for a business meeting to commence without formal bows.

Shop staff and train conductors, hotel employees, janitors and deliverymen all bow to their customers. Even passing a colleague in a corridor will inevitably elicit eye contact and a deep nod.

It's a greeting, and it's polite. But a bow to a Japanese person imparts much more information, with each variety having a nuance that communicates a slightly different meaning.

"Bowing is a key part of greetings in Japan," said Kiyomoto Ogasawara, the heir to the 32nd headmastership of the Ogasawara-ryu school of "reiho," or etiquette.

"Bowing signifies trust and peace by showing vulnerability, as we avert our eyes and expose the head," explained Ogasawara, whose family has served as instructors to generations of shoguns since the school was established more than 830 years ago.

Archery and etiquette

Alongside "reiho," Ogasawara-ryu masters teach the disciplines of archery and mounted archery, an important military skill as well as a religious ritual at Shinto shrines since ancient times.

And while etiquette and archery may not appear to be compatible skills, Ogasawara said incorporating proper etiquette into a person's daily life is required to attain the strong legs and perfect posture needed to have both hands free to fire a bow from a galloping horse.

And that's why, historically, warriors and the elite in society were taught that posture and etiquette are of such importance.

It's widely believed that bowing became the accepted greeting as far back as the Asuka period, between 593 A.D. and 710 A.D. Buddhism was arriving in Japan from mainland Asia and there were shifts in the nascent nation's artistic, social and political mores.

In the Buddhist faith, bowing was — and remains — an important gesture of respect and piety, and it was soon adopted to indicate similar reverence for the elite in Japan's strictly hierarchical society.

And while the samurai no longer rule Japan, the bow has endured as the mark of respect. And failing to perform an adequate bow can still be perceived as a slight, particularly among older, more traditional Japanese.

Today, the bow is the time-honored greeting in Japan, but it's also used to communicate farewell, the start or end of a class, meeting or ceremony and to express gratitude. The bow is also used as an apology, to accompany a request or show sympathy or appreciation. It is deployed when a person is worshipping or at the outset of formal ceremony, and is a critical element of martial arts.

From informal to deeply formal

There are three main types of bow in the Japanese business world, but each starts from the same position: straight back, legs straight and firmly planted to avoid slouching. The bow should then be performed in time with one's breathing.

Bending forward from the waist should take one inhalation of breath. That position is then sustained for the time it takes to exhale and then the person performing the bow inhales again as he or she returns to an upright position.

The "eshaku" bow is a relatively casual greeting, exchanged between people of the same status or when formalities are not as important, and only requires leaning forward to an angle of 15 degrees for a few seconds.

The "keirei" bow is the most common variant in the Japanese business world, and requires the person to lean at an angle of 30 degrees and look at the ground about 1 meter (about 3 feet) in front of their toes.

A "keirei" bow is used to greet clients, join a meeting or during interactions with superiors.

The "saikeirei" indicates the greatest respect to the recipient and requires a bow from the waist of as much as 70 degrees and sustained for several seconds to emphasize respect and sincerity. The "saikeirei" is deployed to greet a very important person, such as a member of the imperial family, to express deep regret or ask for a significant favor.

Men performing these bows are expected to keep their arms rigid alongside their legs, while women often place one hand atop the other in front of the abdomen.

Bows performed in the seated position are known as "zarei" and usually take place on traditional tatami mat floors during traditional occasions, such as the tea ceremony or martial arts tournaments.

All seated bows start from the "seiza" seated posture, with the legs tucked directly below and with the toes pointing straight behind. The person sits on their calves with the elbows pointed slightly out and with the palms of the hands on the top of the thighs.

This position can be uncomfortable for non-Japanese, especially if it has to be sustained for a long time, but Japanese will appreciate good posture.

The "saikeirei" bow starts at the "seiza" position and requires the person to lean forward until their chest is on their lap. Simultaneously, the hands slide forward along the thighs until they are on the tatami floor in front of the knees.

The final position will see the person's face around 5 centimeters (2 inches) from the floor, and the palms of the hands making a triangle on the floor.

The "futsurei" is a less formal variety of the same bow and only requires the person to dip their body until their head is around 30 centimeters from the floor. The "senrei" is even more relaxed and only requires the person to bow about 30 degrees from the waist and have the tips of their fingers on the tatami.

A bow to save one's life

Another, far more rare bow, is the "dogeza," which requires the person to get on their hands and knees and place their face on the ground — and was in the past used when a person was begging for their life after somehow offending a powerful superior.

Matthew Strecher, a professor of Japanese literature at Sophia University in Tokyo, was given lessons in etiquette when he first arrived in Japan in the 1980s. Emphasis was placed on a proper bow and "not just ducking my head briefly," he said.

"Some latitude is given to foreign people when they try to bow and I think Japanese are even quite amused as they watch us try to get it right, but I do think they appreciate the effort," he said. "In the same way, they do not appreciate it when we flout expectations and make no effort at what is quite a special moment."

After more than three decades in Japan, Strecher said he knows when a less formal nod to a colleague in passing is adequate and occasions when a greater expression of gratitude or respect is required.

An appropriate farewell

"If I am saying goodbye, then it is important to bow properly because failing to do that would not be appreciated, and in a business setting we are expected to do the right thing because it is about ensuring the harmony of the workplace," he added.

Kiyomoto Ogasawara said younger generations of Japanese do not grasp the exact meaning of Japan's most important form of unspoken communication.

"Actually, the subtle meanings of different bows are less known nowadays, even in Japan," he admitted. "While they were traditionally learned in the home, I believe that anyone can grasp these nuances, with some studying," he told DW.

"Bowing reflects our cultural identity, so it is vital for understanding our roots and sharing them with others," he added.

"It is part of our culture, influenced by many factors, such as our history and environment. Recognizing and using different forms of bowing is very valuable."

Edited by: Srinivas Mazumdaru