Inthefuture,humansaredividedintoSexNegativesandSexPositives.ThenegativesgetsickiftheyhavesexsotheygotoCafeFleshtoseepositiveswhoareforcedtoperformonstageforthenegatives.Lanaisapositivewhoeveryonethinksisanegativeandshemustdecidewhethertoecleanornot.