Refreshing, fizzy, and fun ramune soda from Shirakiku is the perfect cool drink on a hot day. Ramune is very popular in Japan, where it comes in a wide variety of flavors. Ramune soda is well-known for its uniquely-shaped glass bottle, which comes sealed with a fun marble that acts as a stopper. The marble is held in place by the pressure of the carbonation in the drink. To open the bottle, there is a device to push the marble inward. The marble is pushed inside the neck of the bottle where it rattles around while drinking. Therefore, the drinks are sometimes called "marble soda" outside of Japan.