I just watched the first Kindaichi case files movie (from 1996) and I have some questions

I just started to get into the series and just finished the movie. Maybe it was the fault of the translation or of the story but I was left quite confused by it. Here are my questions:

  1. Why did Takizawa try to kill Rio with an axe?

  2. Why was Mika drugged?

  3. Why did Kindaichi cry at the end?