The costumes used by yosakoi teams vary widely. Happi coats and yukata are the most predominant costumes and can be seen in a wide variety of colors. However, some groups choose costumes that are based on historical attire, popular fashions, or ethnic fashions. Typically, all members of a team wear similar costumes. One of the defining aspects of yosakoi dance is the use of naruko: small wooden clappers that are held in the hands of each dancer. Naruko were originally used in KÅchi Prefecture to scare birds away from rice fields. The traditional naruko has black and yellow beaters on a wooden body, but most modern yosakoi groups create their own naruko, choosing colors and materials that match their costumes. The use of naruko is required in yosakoi dance, but many groups also use other hand-held instruments or props, such as drums, other percussion instruments, flags, batons, and floats.