Koizumi Reiko is a wicked woman who takes pleasure in mercilessly stealing what others hold dear. Seeking new thrills, she sets her sights on seducing her younger sister's husband, relishing in the impending collapse of their happy family. One day, when her sister leaves to attend a friend's wedding, leaving her husband alone at home, Reiko makes her move. Like a beautiful flower hiding poison, her sensual crimson lips conceal a dangerous lust, lurking unnoticed within an erotic, everyday life.