After tranquilizing Heiji instead of Kogoro, he then declares Kento Togano is the culprit, the boyfriend of Ayako Oki. He reveals that the second incident was not for Ayako but for Toshiaki Fujisawa, the train station employee. The reason why Ayako knew that Kento was the culprit is because she decided to cheat off his Holmes test, but when she saw his test, it was blank, because he knew it would never be graded and he was busy preparing for the killing of the host. Kento confesses and reveals Toshiaki and Kanaya were collaborating to publish a Holmes book that had Irene Adler belittle Holmes. He felt insulted by this fan fiction and sought out to kill his targets and later his own girlfriend who threatened to blackmail him for the location of the prized fan fiction copy. After Heiji woke up, he reveals that he was spying on Conan during the deduction (at some point Kogoro hit him upside the head, which woke Heiji up but he pretended to still be asleep), so now he knows the truth about Conan's identity.
Conan and Ran are at Sonoko’s place for her big sister, Ayako. Ayako is getting married so she’s there to meet her new dad-in-law. She’s marrying a man and when they are at their house, they witness a murder outside in the rain. The victim is the dad-in-law, Tetsuharu Tomizawa. The killer at first looks like Ayako’s fiancé, but then they find out he's the younger of triplet sons. Which of the triplets is the real murderer: eldest son Taichi, second son Tatsuji, or youngest son Yuzo?
File 123 - The Triplet Suspects
Conan's second attempt to fire a tranquilizer dart at Sonoko is foiled by Ran who catches him behind the door, prompting him to get Ran and Sonoko to solve the mystery together. When his question fails to guide them in the right direction, Conan tries and succeeds at firing his dart.
Conan is sure its one of the triplets. Since Kogoro isn't with them, he uses Sonoko instead. Turns out it's the eldest triplet, Taichi Tomizawa. He was having a hard time writing a good novel so he decided the best way to do this was to live out a murder mystery. It didn't help that he and his father had a huge fight before the murder, in which Tomizawa Sr. threatened to disinherit him for not living up to the family name.
