When Tomonori Tsuda accidentally shoots an up-skirt photo of classmate Hikaru Ohno, he discovers that (a) she has the Britney Spears approach to panties and (b) she's more of a freak than anyone knew: there's... things up in there! Soon he's her latest plaything; then Hikaru's sister Kei, Hikaru's rival Ryoko, and her (very lucky) boyfriend Koichi are drawn into the vortex of lust and perversion, resulting in three-ways, four-ways, and even five-ways!