Shihori Endo, a beautiful married woman in her prime, lives a quiet life in her apartment. One day, her thong and navy blue going-out panties mysteriously disappear after she had just washed them. At first, she assumes it's just a simple mistake, but as time passes, her confusion grows. Soon, Shihori begins suspecting her neighbors, gradually falling into erotic fantasies. As the mystery lurking within her daily routine deepens, a new emotion begins to stir within her.