After stumbling upon a festival celebrating male genitalia, Mochizuki Yumeko becomes fixated on the penis, not out of desire but sheer curiosity. Desperate to quench this peculiar interest, she delves into the world of nude modeling. With persuasion, she enlists the shy sole member of her school's art club to pose for her, embarking on an unconventional exploration of avant-garde male genitalia art.