Kennedy Ford Montifar is in his eleventh grade. He's been living alone for three years, his mom is living abroad working. He's also a well-known highschool detective, he sometimes helps the police in investigating murders and accepts clients in his home in Ryota Village. Solving crimes and mysteries is his cup of tea. But one day, a random girl asked to be his assistant and then moved in next to his house. He finds her annoying, but he feels nostalgic every time he's with her. He thinks that they have met a long time ago.. And then a mysterious letter was sent to him. Will he be able to solve the mystery of the killings on a certain province? And will he be able to remember the girl from his past?