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.
For a beginner, 'Gojo's First Adventure' is a good choice. It's easy to follow and gives a great introduction to Gojo's character. It has simple language but still manages to capture the essence of Gojo's cool and powerful nature.
There were a few heart-wrenching novels that could make people cry until they suffocated. These novels included The Outsider, The Glass, The Deposed General, Mud, A Woman's Story, A Gorgeous Beauty, There Was a Man Who Loved Me Like His Life, Late at Night, Intoxicated, and The Rest of My Life, Please Give Me More Guidance. These novels were famous for their affectionate descriptions and touching plots, which made the readers experience a strong emotional impact during the reading process, and even cry until they suffocated. These novels used different story backgrounds and characters to show the theme of love, family, fate, and so on, which resonated with the readers. These novels were good choices for readers who liked heart-wrenching novels or readers who sought emotional venting.
My knowledge doesn't have anything about the supporting actress crying again. If you have any other questions about the novel, please let me know. I'll do my best to help you.