Yukie breaks down. She admits to the murder but says, "He took my sister’s future. He deserved to die. And that locket... he didn’t deserve to wear her face."
Yukie explains the circumstances of her husband’s disappearance. Three days ago, Keisuke left their home in the morning saying he was going to visit a construction site in the neighboring city. He took his car. He never returned, and his phone has been turned off since that afternoon. The police tracked his car’s GPS, but the signal was lost in a remote mountainous area on the outskirts of town.
Yukie discovered the truth about the locket one year ago. She found the old photo and recognized her sister. She realized her husband was the man who killed her sister. She pretended not to know, but she began planning her revenge. Detective Conan Episode 406
This episode is an anime-original story (filler) that aired on June 13, 2005. It is a single-episode case featuring Conan, Ran, and Kogoro Mouri. Opening Scene: The Afternoon at the Mouri Detective Agency
The episode ends with Kogoro waking up, having no memory of the brilliant deduction. Ran is quiet, and Conan looks at a photograph of the Sonodas on their wedding day, wondering how something meant to heal could also destroy. Yukie breaks down
Yukie couldn’t kill him directly because she needed an alibi. So she tricked him. On the day of his disappearance, she asked him to meet her at the abandoned shrine at 7:30 PM, claiming she had discovered something important about his past. She gave him a bottle of water laced with sleeping pills. He drank it on the way, feeling drowsy.
Kogoro inspects the car. There are no signs of a struggle—no blood, no torn fabric. The keys are still in the ignition. In the back seat, they find a briefcase containing architectural blueprints and a lunchbox that has begun to spoil. However, something is missing: the silver locket. Yukie had specifically mentioned it, but it’s not in the car or on the ground around it. And that locket
Conan pieces everything together. He uses his tranquilizer dart on Kogoro and reveals the truth in his "Sleeping Kogoro" voice.
She then went back to the car, smashed his watch to show 2:15 PM (the time she wanted to fake), took the locket as a trophy, and drove back to the city using a back road. Her alibi was airtight because she had carefully planned the timing—the drive from the mountain to her friend’s house and the supermarket was exactly 90 minutes, which she accounted for by leaving the shrine at 6:00 PM, not 7:30 PM. She had set Keisuke’s car clock forward by 5 hours earlier that morning, so he arrived at the shrine thinking it was 2:15 PM, but it was actually 7:15 PM.
