Recently concerned about their body shapes, three sisters—Yumika, Ayano, and Mei—decide to start dieting after worrying about not having boyfriends. Yumika invites a massage therapist, Ayano brings in a fitness equipment saleswoman, and Mei hires an aerobics instructor to train at home, sweating hard through their weight-loss routines. Though they eventually succeed in finding boyfriends thanks to their efforts, their obsession with dieting doesn't stop, and they soon turn their attention toward suspicious slimming pills.