A long sleeve underwear for summer that prevents sunburn by using a material called “Cold Black®” for the sleeves, which reflects direct sunlight to keep you cool and protect you from sunburn. The body uses “Cool Fit Dry®,” which quickly absorbs sweat to prevent stickiness and maintain a dry feel, ensuring outstanding comfort. The sleeves also fit close to the arms so they reduce air resistance without fluttering, making it an underwear that almost feels like you are wearing arm covers.