Background: Haibara Ai has developed a small part of the antidote to APTX4869, which can bring her and Kudo back to the way they were in the first grade of junior high school. In order to deceive others, the doctor lied that this was an experimental drug he had created. On the day of sister Haiyuan's death, she was in a very gloomy mood and transferred to Qingxue. Haiyuan, who originally hoped to spend time with Shinichi peacefully, never expected that the organization would actually send a group of killers to sneak into the world of tennis... People were being victimized one after another, making it impossible for Haiyuan to sit quietly and watch. At the same time, the appearance of Ito Yuan, who was an acquaintance of her sister, also made Haibara very conflicted. The story between Aigaku's Echizen, Hyotei's Atobe and others, and a series of events lead to an unexpected ending...
Note: This book is narrated in the first person. The "I" in the book is "Haiyuan Ai".