Ten years ago, a young Kudo Shinichi meets Akai Shuichi, his brother Haneda Shukichi, his sister Sera Masumi, and his mother Mary at the beach. At the beach, a car falls off a cliff and into the ocean. Shuichi attempts to rescue the man in the sinking car, but he died instantly. While underwater, he notices a bag full of brand-name watches with price tags attached in the back seat of the car. Shuichi believes the car is involved in some kind of criminal case and searches for the passenger who has blended in with the crowd...