Smartphone is an essential product in our life today. However, one inconvenient weakness is that the battery discharges so quickly. It is annoying to bring both a cable and an adapter. Also, it often happens that there is no 8-pin cable even though there is a 5-pin cable. The development of Cable Case for iPhone 5S focused on this inconvenience. An 8-pin USB cable is stored in a grooved part at the back of the case. So users can charge their mobile phone anywhere they get to an USB slot. The arc shape that is made because of a cable helps comfortable grip feeling.