Paradise Kiss:
It's name of the group founded by Miwako, Arashi, Isabella and George and also the name of their atelier.
The atelier was originally a bar owned by George's aunt, but when it was closed they created into it their atelier.

Yazawa Gakuin:
See its dedicated section here.

Happy Berry:
Miwako's sister's brand name. More information here.

Velvet Goldmine:
Velvet Goldmine is a famous and glamour film, really loved by Yazawa-sensei. This film is constantly present into the series, and in particulary, George character is heavily inspired by this film. ^_^

Three Top:
It's Shimamoto's Model Agency. It's the agency for which Yukari starts to work.