The serial murders all seem to be related to the car accident 10 years ago. Your parents were driving home, when a truck slammed into them, killing them immediately. The driver was nowhere to be seen. Your brother Yoru believed that they were murdered and it wasn't an accident as they claim, so he became obsessed with finding the truth. One day, he disappeared for years. It was announced that he was dead. No body was found. Now, it appears he is the serial murderer, but you're the 'culprit.'