Ooka Momiji's Challenge (Part One) Ran receives an e-mail from Momiji Ooka. The message says, "I have a code that I want you to solve for Shinichi Kudo. A housekeeper who worked for a wealthy family for many years has died, leaving a cipher for her four sons. She was a mystery lover and sent one cipher to each of her four sons so that they could work together to find the treasure. Shortly after they shared the cipher, the eldest son lost touch with her. He said that he might have gotten into trouble and asked them to solve the code and look for him. Momiji is coming to Tokyo on this day to tell us more about it.