Fun fact: There are several ways to avoid being killed by Kuchisake-Onna. Including but no limited to:
1. Throwing hard candy at her. She'll go after the candy.
2. Asking if she thinks YOU'RE pretty, she'll get confused allowing you to run away.
And, the MOST Japanese escape ever.
3. Telling her you're busy with a prior engagement and need to be excused. She will then apologize to you for being rude and leave you alone.