Toge Inumaki is important too. His special cursed speech ability makes him stand out. Also, the principal of the school, Masamichi Yaga, is likely to be important as he is in a position of authority and has an influence on Gojo and the other students. There could be other characters like the members of different clans that also play roles in the complex web of the story.
In the search results provided, he did not find any relevant information about the novels recommended by the two male leads before and after the separation.
Before the exam:
I was so nervous that my palms were sweating and my breathing became rapid. I've been thinking about the contents of the exam, wondering what I should do if I accidentally do a wrong question. I didn't know if I could do it well, so I kept reminding myself to calm down. But I really can't calm down. I feel like I'm about to explode.
After the exam:
I was relieved when the exam was over, but my heart was empty. I didn't know if I had really mastered the contents of the exam. I thought back to my performance in the exam and wondered what I would do if I got a question wrong. I began to worry about my future, wondering if I had the ability to do what I wanted.