Help me find a Manhwa

If i remember its a high school one and the mc is a girl who went back in time before her fremeny? Killed himself even though he was really cheerful ect. And she was kinda an outcast and only he really talked to her and sshe hated him for that but in the second life she tries to be his friend to understand why he did that. I hope this makes sense lol I also think summer was in the title? I might be completely wrong tho