Can you recommend a novel with a refreshing style? Recently, I wanted to reread it, but I forgot the title of the book. I feel very troubled. Can you recommend it?

LZ 90s, I think I read it in junior high school. I remember that the author of that novel was quite famous at that time. LZ could only vaguely remember a few details. I hope the awesome god can answer! The story began with a man and a woman. The two were good friends. The man was the typical handsome, smart, and good-looking school hunk type. The woman was the kind of problematic girl who did not study well and hung out with gangsters every day. However, the two of them had a good relationship (they seemed to like each other). Then, the girls often changed their boyfriends. One of them was a gangster called Ah Kai, but they broke up very quickly. Later on, for some reason, the girl started to study very hard. In the third year of high school, she was actually promoted from the last class to class four. The boy was still in class one, the best class. The girl had never had any same-sex friends, but she became best friends with a very obedient girl in Class 4. The obedient girl told the girl that she had always been in Class 1, but because she had a crush on someone, her grades dropped and she slipped to Class 4. Later on, the girl found out that the obedient girl liked her previous boyfriend, Ah Kai. The obedient girl pierced four ears for Ah Kai (because the word 'Kai' was four strokes) and gave her first time. However, Ah Kai had never liked the obedient girl. He had always liked the female lead, but the female lead ignored him. Therefore, Kai often messed around with other girls and even got one girl pregnant. The obedient girl was so obsessed with her that she stole her father's money and gave the money to Kai to help him abort the girl. Later, he forgot why the obedient girl jumped off a building and committed suicide. Ah Kai finally realized how much the obedient girl loved him and was hurt, so he left the city and went to work elsewhere. There was another detail. In Class 4, there was a boy who was a good friend of the male protagonist. He was very smart but did not study. The boy was entrusted by the male protagonist to take care of the female protagonist. In order to take care of the female protagonist, he planned to enter the same school as the female protagonist. When the boy asked the female protagonist which school she had applied for, the female protagonist told him a random school, but later she quietly changed her choice. That boy was actually very good, but he deliberately didn't do the last few big questions during the female protagonist's entrance examination. However, because the female protagonist changed her choice and went to a good school, the boy went to a very ordinary school and was very angry. However, that boy changed in that school and began to show his talent. He became the first in the school and the female protagonist was very happy for him. After that, the female lead and the male lead went to different schools, and there seemed to be very little contact. After that, I forgot about the ending... Forgive LZ for being so long-winded, but this is the only detail I remember. Please help me! Please give me the title! Kneel and thank him!