Kyaa~ There's a marble! No, it cannot slip out and choke you unless the neck and cap were broken. It's fun to open though. The marble is at the top, and you push it into the drink with a stopper. [I LOVE my phone, it takes awesome pictures.]
In case you want to try, and my explanations suck, then: http://www.wikihow.com/Open-and-Drink-a-Bottle-of-Ramune-Pop
xoxo, Candy