Take On Me

When digital photography nerd Tomonori Tsuda accidentally shoots an upskirt photo of classmate Hikaru Ohno, he discovers that (a) she has the Britney Spears approach to panties and (b) she's far more of a freak than anyone ever knew.
He gamely tries to use the photo to pressure Hikaru into sex, only to have the tables turned on him as they embark on a wild, woolly, and very wet sexual relationship in which games, domination and humiliation play an enormous part.
(Source: Animecornerstore)