Hi, I'm from Finland, but I haven't got a clue of what Arja means. Some say it's a Finnish version of the Greek Ariadne, but I doubt that, since Arja is a relatively new coinage. It entered the Finnish name-day calendar in 1950 together with other coinages for female names such as Merja, Pirjo, Tarja and Erja. As you can see, these names for a group that's probably intended to sound fresh, cheerful, happy, and most of all, very different from the traditional names. Today, most people named Arja are in the fifties; but I know a couple of Arjas who are around 25. It's considered a plain but not overused name, nothing fancy about it.