First off, I am a play-by-post or "forum RPer" so I don't understand what you mean by "What system?"
Secondly, yes, I am in the U.S.A.
And thirdly, as to the How are we playing? it's really simple. I write an intro and you respond to it as though we were writing a book. As you may have guessed it is a Twilight Princess-Majora's Mask idea involving a "What if Twilight covered Termina after it failed to take over Hyrule?"
The situation is simple enough, however this is what happens to Link's family as if he had never left Termina and instead his son or daughter(that's up to whomever plays this character) were to set off on an adventure in Termina. The reason this could be a group is because Navi could be found/Midna could get cursed AGAIN/ The Happy Mask Salesman could show himself again/Shadow Link could come back/Fierce Deity and Majora could show themselves/And of course every single mask doesn't have to be worn by only the new hero.
I do in fact have a plot, and it involves allowing for any of the situations above to happen if there are people who want those characters.