Japanese Ramune marble soda opening method?

Question

I just press down w/ a constant force on a flat surface. no matter how i open it, it always erupts.

Answer 1

Make sure that the soda is COLD and hasn't been touched for a while. I try to open it gradually then letting some of the gas escape before tottally opening it.

Answer 2

Treat it like a woman, firmly but gently ;)

Just like any other soda, you have to be careful. Rarely erupts on me but then again, I haven't drank too many as an adult so the binding suction pressure of those marbles could have become much tougher than when I was a kid (strong thumbs).... and rush that bottle to your mouth as fast as you can to get any spillage. (I'm glad your question was not how to get the marble out of the bottle)