The story is about a young woman, working as a police officer or something. She is in love with a fellow collegue. While visiting her old high school she meets a wanted criminal. Said criminal was about to commit suicide by jumping of a building. The main heroin wanted to prevent this, but falls with him. Instead of dying she somehow travels back in time into her younger self back in high school. There she meets this criminal, who still hasn't committed any crimes. She now wants to "re-educate" him, so that he won't end up the same as his future self. Meanwhile they fall in love with each other.
Her previous crush from the future somehow ended up in the past as well and they collaborate together to safe the "criminal".
I remember reading this manga back in 2017. Back then it was still ongoing.