13 Sister Brands You Didn't Know Are Related

When you're out and about shopping from store to store, it's easy to think of iconic fashion brands as characters, with whims, quirks, defining charms, and fatal flaws. But any good ingenue also has a counterpart — that entity who flits between the spotlight and the shadows, who's made from the same blood and bones, and who knows her better than anyone else (for better or worse). You know — a sister.

In honor of National Sisters' Day, we're revealing which brands are actually kinfolk, related by their parent company. Sure, everybody knows Gap, Banana Republic, and Old Navy are in the same family, and that H&M and COS share DNA. But, for example: Did you know about Uniqlo and Theory, too? Click through the slideshow ahead to discover which of your favorite luxury designers and fast-fashion retailers are closer linked than you think.