Ten years ago, Masumi, taken by her middle brother Shukichi and their mother Mary, reunite with Shuichi who did not take the test yet to become an FBI agent in the Atsuhama Beach, Shizuoka Prefecture. Mary had an off-screen fight with him where they both managed to injure each other's eye. Through out the case Mary warns him to stop investigating the disappearance of his father. The Akai family also encountered Shinichi, Ran and Yukiko who also happened to be there. Shinchi introduce himself as "Holmes Apprentice". All of them end up being involved in a case where two robbers robbed a watch shop with one of them accidentally got killed in an accident, and the other was still on the run.
Accident
Location:Atsuhama Beach
Victim:Man
Age:Unknown
Cause of death:Broken neck
Suspects:Unknown
When the vehicle crashed into the guardrail, the driver's head smashed into the windshield, breaking his cervical vertebrae in the process. The man was killed upon impact.
Part 2
Robbery
Stolen:Watches
Suspects:Shigekatsu Fukumizu, Yasue Kitamori, and Raiya Ooami
The other robber is Yasue Kitamori. Yusaku and Shuichi explain that they knew this from the fact that she is not wearing a swimsuit under her outerwear, and her purchase, a pair of beach sandals. Since the other robber fell into the sea, the bank notes in the robber's wallet would be drenched and thus too suspicious to pay with. Unlike the clothes the other two suspects purchased, Yasue's sandals were cheap enough to pay for them with coins instead. Secondly, Yusaku and Shuichi noticed that Yasue's watch was stuck at 10:10. This time is what watches on display at shops are usually set to, since the handles don't obstruct the brand logos this way. All branded watches have serial numbers, so it will only take a simple comparison between Yasue's watch and the ones stolen during the robbery to prove her involvement in the crime. Yasue confesses and explains that during their escape, she and her partner got into an argument over Yasue taking the watch from the loot for herself and that this argument caused the car crash.
After the case, Shuichi said that he enjoys to solve the case speaks of being "infected by the disease called curiosity," Mary is immediately reminded of Tsutomu. Shukichi is also reminded of Tsutomu when Mary tells Shuichi to "purge the fog that covers the truth". Shinchi said that he would like to become a detective as Shuichi, and Masumi calls Shinichi as 'Wizard'.
Conan realizes that Masumi knows that he is Shinichi Kudo, the Akai family's middle brother is Shukichi Haneda, and that their mother is Mary, now somehow shrunken.
Masumi thinks to herself that while Conan has finally remembered her, and has remembered that he made Shuichi smile and laugh when she could not, there is another reason she calls him a "wizard", a reason which he does not know.