There's a common story that people find mysterious handprints on their cars on their way home from a kimodameshi. test of courage

I once had a classmate who showed me a car that actually had this happen to her when she was in elementary school.

On the way home, she was caught by the sound of someone banging on her car from outside.

Her family left the scene quickly and was fine, but she was troubled when the handprints wouldn't come off, even after washing.