Search the internet, books and magazines for pictures of Harajuku girls. This not only will give you a good idea of the style you are trying to create, but also offers design inspiration taken straight from the outlandish costumes. You will notice lots of black, a Gothic Lolita style, cyber punk influences and brightly-colored hair, all combined with traditional Japanese clothing, such as kimonos and fans.
Place a Japanese cityscape mural on one wall to give the room an atmosphere of a bustling Japanese city. Paint the other walls in neutral colors, such as soft grays.
Bring the Gothic element of Harajuku fashion into your room with the use of black accents. Paint woodwork black and add black satin bedding, black lace tablecloths, elaborate chandeliers and candelabra, and PVC and leather cushions.
Add colorful ribbon to cushion covers and pillow cases to represent the Goth-style corsets that are so popular with Harajuku girls. Fishnet is another typically Harajuku Goth-style fashion accessory, and this can be used to cover items, such as picture and mirror frames.
Use bright, neon colors to represent the cyber-punk aspect of Harajuku fashion. A cushion, throw, floor rug or pillow will be sufficient for these colors.
Look for a few traditional Japanese accessories, such as fans and chopsticks. These items can be either mounted directly onto the wall, framed, or displayed as tabletop accessories. Also, add a touch of Japanese patterned fabric in the form of "Noren" -- Japanese curtains.
Create an unusual focal point in the room with a mannequin dressed as a Harajuku girl. A Gothic corset, fishnet sleeves, cyber-punk skirt, bright wig, Gothic collar and face bandana all are items that make up a Harajuku costume. Alternatively, find a picture of a costume you like and recreate the look.
Display a combination of wall art. Combine traditional Japanese prints with Gothic and cyber-punk artwork and Manga art.