Yu Shu went through the book.
After Yu Shu accidentally read Mary Suwen, he lost his mind.
Yu Shu in the book is purely cannon fodder and only has two scenes.
One is about being a passerby during the high school days of the two protagonists.
One was when the attacker and the subject reached the top and continued to be passers-by.
Yu Shu: What can I do for you?
Intention: Relaxed