Seeking a youth campus novel

The male and female protagonists met because of a girl when they were young. That girl was their mutual friend. It seemed that the male protagonist liked her and later fell ill and died, so they matchmade the male and female protagonists.
The male and female protagonists lived together and were in high school. The male protagonist had a tumor and secretly took medicine. It seemed that there was a woman in their high school who liked the male protagonist and was violent to the female protagonist in school. She was slapped by the male protagonist and bore a grudge. Later, the male protagonist died in a car accident (it seemed to be related to this woman, but he did not really die).
After the male protagonist left, the female protagonist changed into a different person. She was cold and aloof. When she was in university, everyone in her school said that she had mental problems. Later, a hooligan second male lead came to be her deskmate. It seemed that once in the classroom, the female protagonist had a stomachache or something. The second male lead princess carried her to the infirmary. Later on, the two of them dated and met the male protagonist when they were choosing a wedding dress or holding a wedding.
Aiya, it's a novel from around 2010. I can't remember clearly. If there's a god who knows, please tell me.

Answer 1

This was a novel about a group of young people growing up in high school, including love, friendship, studies, and future plans. This novel had a strong youthful aura, but it was also full of imagination and adventure elements.