This little "key holder" is actually what is called "strap" in Japan, an item that could be attached to mobile phones in the past. Smartphones often do not allow to cling these straps anymore, however, they are still great as accessory on key rings, bags and cases etc...
This model is a perfect miniaturized representation of a whole white or blue Judogi with a black belt. Both of them have the KuSakura red "S" logo presents on the jacket, the pants and the belt.