Sonoko says Naoya Higashida should be the real culprit in the story, so
Genta came up with having Higashida's given name being Ichirou (one) and the meaning of the dying message being number one.
Ayumi then suggested that Oshita was trying to say "one" in English (pronounced as "Wan" in Japanese) and that Higashida was a dog instead.
Mitsuhiko then suggested that Oshita was an alien who was shocked and having his heart stopped because Higashida found out about the fact. He then fantasizes it into a sci-fi parody, making the Detective Boys run away with the alien from the police. Sonoko however rejected all of these suggestions.
Later, inside Mouri Detecive Agency. Conan was able to come up with a plausible resolution after seeing the text sticker on the detective agency's windows and Mitsuhiko talking about how Genta was making pizza grease dripping everywhere. The resolution he came up with is as follows :
"NEWS" can be used to represent the cardinal directions. "N" stands for North (北, Kita), "E" stands for East (東, Higashi), "W" stands for West (西, Nishi) and "S" stands for South (南, Minami).
When sunlight came in through the windows, the letters of "NEWS" written on them appeared as shadows on the floor.
After Higashida left, Oshita then saw the shadows as the sunlight came, and he used his left hand to point the shadow of the "E", revealing that the culprit is the one who has "East" in his name.
Oshita grabbed Higashida's left arm with his right hand soon after he had been stabbed, which touched Higashida's watch. Since he was eating pizza just before that, a greasy fingerprint appeared on the watch. And because Oshita didn't wear a watch, he grabbed his belt with his right hand, signalling that the culprit's (watch) belt should be checked.
The culprit's motive is that he got fed up with the president trying to make the magazine sell by writing fake reports, which went against his will and his love towards the magazine.
Conan told Sonoko as Shinichi using the Voice-Changing Bowtie. And she accepted this story. A week later, as the time came for the stage play, Sonoko ended up catching a cold and couldn't speak, thus Ran had to replace her. The last scene was also altered to an action scene where Ran take out the culprit.