Once-A-Month Present Threat Case

Situation
Once a month for the past two years surgeon Masayuki Ogawa has been receiving anonymous toys and money valued over 25 million yen. He asks for Kogoro's help to determine who is sending the gifts. On Conan's suggestion, they review Masayuki's patient history. During the investigation Ran begins to suspect that Conan is actually Shinichi. When Conan plays a video game Masayuki received, Conan discovers that it belonged to a child named Tomoya Ogino who died during one of John's operations three years previously.

Resolution
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 * Evidence
 * Two years ago, an anonymous person started sending Dr. Ogawa boxes full of toys, along with some cash, on the first day of each month. And once every year on a winter, Morning Glory flowers get delivered to the hospital where he worked.
 * Dr. Ogawa received the flowers on that exact same day. However, this time the money came separately with a letter.
 * Coincidentally, as Conan was playing with one of the toys, he discovered that there was a username in the video game that was not of Dr. Ogawa's five-year old son, Yuta. He rummaged through patient records and found that Tomoya Ogino, indeed, was a kid who passed away three years ago on that day after being operated on by the doctor.

Conan deduced that the presents were not given to Dr. Ogawa in gratitude, but with grudge and hate, by someone related to Tomoya Ogino. The toys belonged to Tomoya and was send as a memento of the boy. The money was from the life insurance.
 * Conclusion

Sensing that Yuta was in danger, they rushed and found him in a park near his kindergarten with an unknown man. Turned out, this man was Tomoya's father, who planned to end Yuta's life on the same day and at the same age that Tomoya died. The father lured Dr. Ogawa and Yuta with his son's old toys and life insurance money, and sent his son's favorite flower to commemorate his death.

Had Conan not interfered by kicking a nearby soccer ball towards the man, Yuta wouldn't have been saved from an ill fate. Mr. Okino, facing Yuta's gratitude for the toys and is reminded of his son, breaks down and finally admits to himself that Tomoya's death wasn't the doctor's fault. However, Dr. Ogawa decided to forgive the culprit, citing that, as a father, he understood how devastating it was to lose a son.

As for Ran, she stopped her suspicion that Conan was Shinichi. He had asked Professor Agasa to call Ran as him using the Voice-Changing Bowtie.

Tomoya's father could not accept that Tomoya died not of surgical complications from Dr. Ogawa's hands. He blamed Dr. Ogawa and planned to have his revenge by taking away what he believed was also taken from him: a father's son.
 * Motive

Manga to anime changes
Main article: List of differences between the manga and anime


 * In the manga, this story takes place after the Luxury Liner Serial Murder Case, as Ran gets a letter from Natsue who mentions that she and Takeshi are living a more quiet life on the ranch. Natsue tells Ran to give her regards to her "detective boyfriend", which sets up the story. The anime version starts with Ayumi, Mitsuhiko, and Genta asking about Shinichi and whether he is Ran's boyfriend.
 * Additionally, Ran's recollection of the past cases included a flashback to "Luxury Liner Serial Murder Case" in the manga only.

Continuity

 * This is the first case Ran get's suspicious of Conan. The second case this happens is in "The Cornered Famous Detective! Two Big Murder Cases".