Hanhaba obi (a half-width sash) (半幅帯)
The hanhaba obi is a kind women's obi sash used in Japan. It is also called "Hoso obi" or "Yonsun obi."
This name derived from the fact that it is made after folding a textile of standard width (about 36 cm) in half (yonsun (12.12 cm) measured by kujirajaku [a measuring stick used in kimono-making]).
It is an informal obi that is not used in public places in principle, except for the cases where it is used invisibly, such as under haori (a Japanese half-coat) or uchikake (long outer robe). It is made of cotton or Hakataori textile.
It is generally used for yukata (Japanese summer kimono), wool kimono, tsumugi (pongee) kimono and kasuri (cloth with splashed patterns) kimono. Obijime (a sash band) and obiage (a bustle for an obi) are seldom used in tying a hanhaba obi because it is tied without making a big knot, such as bunko-musubi knot, kai no kuchi knot (Japanese traditional clothes) or ichimonji-musubi knot.
To create a glamorous air in the dancing of traditional folk songs, the hanhaba obi made of nishiki (brocade) is often used for yukata with an unified picture across the entire canvas of the kimono, which is not interrupted at the seams. This is because folk dancing, which originated from people's folkways and has become theatrical art, needs glamorous air as theatrical art while maintaining traditional appearance such as costume etc.
Therefore, it doesn't mean that the hanhaba obi is generally recognized as a costume for noticeably cheerful and formal situations or such places
Unlike the case of yukata or the above dancing, female dancers of Awa-odori dancing festival put on juban (undershirt for kimono), susoyoke (half-slip) and tekko (covering for the back of the hand and wrist) and tie a hanhaba obi made of black satin in karuta-musubi knot (a black Nagoya obi is also used).
When wearing women's hakama (formal divided skirt) at coming of age ceremonies or graduation ceremonies, they tie the hanhaba obi in ichimonji-musubi knot and put hakama on it in order to make their back style look beautiful. Nishiki is sometimes used. It is a figure of hanhaba obi when it is used in a public place as a substitute for kaku obi (men's stiff sash).