A yukata is a cooling garment to wear. It consists of one big piece of cloth with two wide sleeves. It's not always obvious how to wear a yukata properly. An obi (belt) is used to keep the yukata from falling open. Also, a special type of sandal, geta, which only has one strap, is worn with the yukata.
Traditionally yukata were mostly made of blue-printed cotton but today there is a wide variety of colors and designs. Many young women wear yukata today, arranging them in various ways.