Desire to make severe punishment for sex crimes

/ News Recap /

6 times sexual assault for 12 years old girl.
A defendant Kawai, a former junior high school teacher, was sentenced to 4 years in prison.
The defendant also recorded video of sexual assault and made child pornography.

Source/ Yahoo Japan, Ishikawa TV

/ My opinion /

I think the punishment is too light!
There were 1,105 comments on the article.
All of the comments were angry.

I feel a strong desire to make extremely severe punishment for sex crimes against minors.

I'm wondering how to change the laws.

How can I bring this problem closer to many people?