itching my brain

yesterday, i remembered something really random. I have no idea if it is from a movie, an anime, a tv show, a story, or a manhwa. I just remembered the plot. Honestly, I have no idea if this is even a real thing, or a plot I made up a long time ago.
!!TRIGGER WARNING!! I am going to be talking about suicide

What I remember is a boy who was trying to kill himself. He went to a convenience store to buy cigarettes (posed as an older boy) but the cashier knew he was underage. I think the cashier was around the same age as the boy. I am not sure about this next part, maybe this is from an entirely different thing: The cashier had some type of power that allowed him to see into the future?? So he could tell that the boy buying the cigarettes was going to kill himself. Again this part was probably not part of the plot, it was just something I remembered in the moment.

In this next part, I only remember these two scenarios, but I have no idea which one correlates to the actual plot.

1.) The boy goes outside of the shop after being denied cigarettes and then he tries to kill himself by running into traffic. The cashier from the convenience store stops him just in time. the cashier recalls that in his younger years, his mom killed herself by running into traffic, and he was left alone. He remembered he too felt alone and lost because he had witness his mom die in front of his eyes. He became severely depressed and tried to kill himself multiple times because he thought he was meaningless. He couldn't go to school and worked multiple jobs at once.

2.) The boy who tried to buy cigarettes is now on top of a roof in a building, and tries to jump. The cashier is up there with him and is trying to convince the boy to not jump. He says something along the lines of: "If you jump, I will jump too because I will feel sad that I couldn't stop you" He gets onto the ledge with the boy. The boy gets off of the ledge and then breaks down. The cashier tries to console the boy and the boy tells him that he is stressed out because of his parents. His parents are overworking him because they do not want him to be unsuccessful. Determined to help the boy, the cashier makes the boy escort him to his house. At the boy's house, the cashier tells the parents that he will help the boy in his studies, and they do not need to keep overworking him.

I'm sorry if this is super confusing. It was just a random plot I remembered on a car ride. It is itching my brain and I need to know what it is.