This is a portable cup that is similar to a water balloon. When you pour a drink in, the cup expands, and as you drink it up, the cup contracts again. The cup is designed using a traditional Japanese bamboo technique. It is made up of three parts: a bamboo frame, a paper liner and a plastic cap. The bamboo frame and the paper liner support each other and make the cup stronger. The cap is attached to the paper liner and both can be easily replaced although they have been designed to be washed and used repeatedly. This is possible thanks to the advances made in paper manufacturing to make paper more resistant to water and wear and tear.