Why main character in the movie started to change?

[jooyoungpark]

It starts accidentally doesn't it?
Well, in the movie it also says that emotion is like a drug. He accidentally stopped taking it one day and couldn't resist his own "feelings" and start to feel more and more through various events that led him to stop taking the drug eventually

[mirim002]

I was wondering about that. Maybe he just wanted to feel like what it was to feel? Or maybe he just realized how horrible it is without feelings. Or, maybe he realized what the place was like without feelings. In the movie, he dropped his injection. I agree to what Lin said. It could be right when his injection fell, and when he went to get another, he started feeling. So yeah. That's what I think.

[jisu25]

The main character must be regretting the terrible things that he did over the many years as a killer. He must wanted change after the death of his first partner.

[sorn]

He began to feel again because of his dream about his wife. He began to feel those emotions coming back to haunt him again. So he decided to stop take the drug, once your stop taking it, you will began to feel and unfortunately you would want to feel more.

[munisa]

The main character started to change because he dropped the drug that makes your feelings gone. And due to that he got to feel. He got addicted to feeling things that's why he stopped taking the drug. Because he wasn't taking the drug he felt/saw all of the things he didn't see before, he felt bad to all of those people that he was killing and that's when he knew that what he was doing was wrong.
I think that its dangerous if people cannot feel, because they wont feel bad for others, they might become crazy maniacs.

[agneslianaputri99]

I think that he forgot to take his drug once then he start feeling something then he wants to feel it more and more so he realize that life is better without taking the medicine so he stopped. O.o

[woori]

Hello

[akari]

because they have to take medicines which will kill their emotions.