My Sister, My Double: Where's Betty

Valerie, a pretty, young woman, finds a picture in a porno magazine of her twin sister Betty. They've been separated since birth, but now Valerie wants to find Betty. Valerie figures if she disguises herself as her twin sister, she'll find her in the seedy underworld of S&M sex. When she and a lesbian police captain finally find Betty, the twin sister has no recollection of her life - except for the sex slave part.

Image: My Sister, My Double: Where's Betty  - Fantagraphics

My Sister, My Double: Where's Betty