A 17-year-old girl, Shoko Takahashi, stabbed and killed a man living together. Shoko was arrested for the current criminal, but only cried and the truth remained a mystery. At that time, a witness appeared. Masato Serizawa is 19 years old. Shoko and Masato, who hadn't taken a step out of the room, were in contact with each other in a paper airplane correspondence. And...! [Simultaneous recording] Oval in the wind