Duo Halloween Costume: Anna and Maya From "Pen15" This two-person costume idea gives you and your bestie a chance to show off your finest 2000s fashion. Act as awkward as possible to really emulate the characters at your Halloween party. What to wear for Anna: A button-up t-shirt, jeans or a long denim skirt, trainers, and a backpack. What to wear for Maya: A simple t-shirt, capri pants, a backpack, and a bowl-cut wig. Image Source: Hulu