From Chapter 635, he will be your mentor

"Chen Yu, you really have to study hard this time. Xiao Sun is here specifically for you. We wanted to invite Xiao Sun here before, but he was unwilling to come. This time, for you as a student, I specifically applied for a job transfer, and then you really have to study hard with Xiao Sun, and don’t let down Xiao Sun’s expectations of you!" Mr. Yuan said to Chen Yu.