Some brands of Ramune (ラムネ) don't have a removable cap which makes it very difficult to get the marble inside. Here's the easiest way to get the marble out of Ramune (ラムネ) bottles without breaking them. Please be cautious though as you can harm yourself if you're not careful. Children should never attempt this; ask an adult to help you get the marble out.
For those of you who can't figure it out. Here is how to open those tricky bottles.