obijime
Obijime (帯締め, おびじめ) is a small decorative string tied around the obi, used only in women's kimono.
It's about 150 cm (4.9 ft) long and is tied around the obi and through the knot, and which doubles as decoration. It can be a woven string, or be constructed as a narrow sewn tube of fabric. There are both flat and round obijime. They often have tassels at both ends and are made from silk, satin, brocade or viscose. A cord-like or a padded tube obijime is considered more festive and ceremonial than a flat one.