Mayumi has suffered greatly in a world that often seems merciless and incomprehensible. Losing both her parents in a car accident at just thirteen years old left her with overwhelming grief, anger, and despair, making her wish she could escape her emotions altogether.
Years later, Mayumi's sister becomes embroiled in a strange and unsettling incident. Victims receive text messages that simply name a specific body part, which then disappears without blood loss. Mayumi's sister's ex-boyfriend, Kanno, appears to be the culprit, but he denies any involvement. As Mayumi strives to unravel the mystery alongside Kanno, she begins to wonder if he truly is innocent. Could the crime be linked to his fiancee's suicide years ago, or to an artificial intelligence program he was developing that may have broken loose? And even if Mayumi helps solve the case, will she ever find emotional healing in a world that seems to offer only senseless cruelty?
