During the Muromachi age ( 1392 – 1573 AD ), the Kosode, a single kimono formerly considered underwear, began to be worn without the hakama ( trousers, divided skirt ) over it, and thus began to be held closed by an obi " belt ".

A modern use in this manner includes tying the obi ( or belt ) of a martial arts keikogi.

Note that the youth on the left is wearing a distinctly feminine kimono ( red / pink color, double-wide obi belt ).

The systematic use of belt colour to denote the rank was first used by Kano Jigoro, the founder of judo, who first devised the colored belt system using obi, and awarded the first black belts to denote a Dan rank in the 1880s.

In Japan, books frequently come with two dust jackets – a full-sized one, serving the same purpose as in the West ( it is usually retained with the book ), and a thin " obi " (" belt "; colloquially " belly band " in English ), which is generally disposed of and serves a similar function to 19th century Western dust jackets.

Upon Miyagi's death in 1953, Miyazato inherited his teacher's training equipment, and the family also passed on Miyazato's gi ( uniform ) and obi ( belt ) to him.

In the majority of dōjos today, the jōdōka essentially uses the same clothing as practitioners of kendō, minus the armour and other protective padding: A blue / indigo uwagi ( jacket ), an obi ( belt, often the same type as used in iaidō ), a blue or black hakama ( wide trousers used by samurai ).

An obi belt to indicate the wearer's level of kyu or dan grade may also be worn.

This cut also has a longer lapel that prevents it from riding up over the belt ( obi ).

Many karateka tend to wear their obi ( belt ) much longer than judoka and other martial artists.

The jacket is also held closed by the belt or obi.

A judogi comprises three parts usually cut from different styles of fabric, a very heavy uwagi or jacket, a lighter canvas style shitabaki or pants, and a cotton obi or belt.

*: The sageo is the cord used to tie saya to the belt / obi when worn.

The sageo ( cord ) that secures the saya of the sword to the obi ( belt ) goes through a hole in the kurikata.

A woman's kimono has additional length to allow for the ohashori, the tuck that can be seen under the obi, which is used to adjust the kimono to the individual wearer.

The kimono and obi are traditionally made of silk, silk brocade, silk crepes ( such as chirimen ) and satin weaves ( such as rinzu ).

Boys of age five could wear hakama for the first time, while girls of age seven replaced the simple cords they used to tie their kimono with the traditional obi.

The obi is a very important part of the kimono.

* The obi is traditionally part of a Japanese kimono.

Japanese-style mourning dress for women consists of a five-crested plain black silk kimono, black obi and black accessories worn over white undergarments, black zori sandals and white tabi split-toe socks.

The Japanese equivalent of a sash, obi, serves to hold a kimono or yukata together.

Tōgane is home to the Kurenai-kai School of Japanese embroidery, which produces handmade obi and kimono in the traditional Japanese style.

Initially the wide obi was used ; as practitioners trained in kimono, only white and black obi were used.

The shitagi was like a short kimono with a button at the neck and an thin attached waist cord ( obi ).

At that time, these obi were not the belts karateka and jūdōka wear today ; the students were still practicing in kimono.

They wore the wide obi still worn with formal kimono.

The obi for men's kimono is rather narrow, wide at most, but a woman's formal obi can be wide and more than long.

Nowadays, a woman's wide and decorative obi does not keep the kimono closed ; this is done by different undersashes and ribbons worn underneath the obi.

The contemporary women's obi is a very conspicuous accessory, sometimes even more so than the kimono robe itself.

There are many different types of women's obi, and the usage of them is regulated by many unwritten rules not unlike those that concern the kimono itself.

Certain types of obi are used with certain types of kimono ; the obis of married and unmarried women are tied in different ways.

Often the obi adjusts the formality and fanciness of the whole kimono outfit: the same kimono can be worn to very different situations depending on what kind of obi is worn with it.

A common folk etymology attributes its name to the mixed Portuguese and Tupi phrase morro obi, which would mean " green hill ", but this is disputed.

This obi would serve as the court of the first instance, depending, of course, on the nature of the offense or crime allegedly committed.

If the complainant was not satisfied at this point, he would appeal to the obi of the quarter and the leaders of his family could be summoned to defend their judgment

* or is an obi that has been sewn in two only where the taiko knot would begin.

As married women in the Edo period would have, they blackened their teeth, and tied their obi in front.

The obi itself often requires the use of stiffeners and ribbons for definition of shape and decoration.

A fukuro obi is often made so that the part that will not be visible when worn are of smooth, thinner and lighter silk.

The knots used for hanhaba obi are often simplified versions of bunko-musubi.

As it is more " acceptable " to play with an informal obi, hanhaba obi is sometimes worn in self-invented styles, often with decorative ribbons and such.

* is a very informal obi made of soft, thin cloth, often dyed with shibori.