デコラ (dekora) is a Japanese word shortened from the English word "Decoration". And that's what Decora is. Decoration. Wearing as many accessories (and sometimes even toys) as possible. You'll be able to hear a Decora-chan coming a mile away - with all their necklaces and accessories banging against each other
Like any other trend, there are several rules to go by with Decora, but generally there are no rules. It takes months of practice and mix-n-matching to get your Decora look perfect. Decora is more than just a load of hairclips on your head and five or so necklaces.
Many look to Decora for inspiration, as it just screams "LOOK AT ME". Different fashions such as 'Scene' have taken a few ideas from Decora, making it even harder to look truely Decora.