On the way to the investigation, Ran and Conan are arguing, and Officers Megure and Takagi ask them what's going on. Ran says Conan is hungry and wants to eat the cake on the table.
Actually Conan was trying to say that there were marks on the cake that had been cut in half, that there was a strange smell inside the flowerpot, and that there was a coffee cup on the desk that was used as a pencil holder. In fact, there was a cake and coffee for two on the desk at the beginning, and after the murder, the coffee from the other cup was poured into the flowerpot and the coffee cup was disguised as a pencil holder.
Yenai had a fork hidden on him and said he was going to use it to eat the cake, and as for the marks on the left and right feet of the chair, he made them himself. That's when Conan anesthetized Uncle Mouri, the sleeping Kogoro's deduction show began.
Stainless is not the murderer of Nakame, he is harboring a certain character. The real murderer of Nakame was Maiko Kusumi, and it was said that Maiko came to Nakame's house first in the beginning, and when she was about to eat with Nakame, she secretly poisoned Nakame's coffee cup, so that Nakame would drink the poisoned coffee and die.
Then Maiko disguised herself as a suicide by using the same technique as she said at first, and then called Yenai again and jumped to her death after telling him everything that had happened. Upon hearing this, Yenai vehemently denies it and says that he was the one who killed Nakamura. Conan goes on to say that the reason for Yenai's soaking wet body is because he found Maiko's body underneath Nakame's house in the rain and hid the body in the back of Nakame's car so that he could pass himself off as the murderer.
The police later discover that Maiko's body was really hidden behind Nakame's car and take Yori away for obstructing the investigation. The case ends in a torrential downpour of rain, as if crying out in tears.
After the case is over, Ran and Conan prepare a cake at home, and when Ran sees that it's only one slice, she plans to split it into two. But Conan says he's not hungry anymore, so Ran gives the cake to Kogoro and Conan is not in the mood to eat it because of the heavy rain as a reason, probably an aftermath of the sad case in the heavy rain not long ago.