Why is Akira behaving in such a timid manner? He was 29 in his previous life when he died, and at that point he had become highly successful and weahtly, was leading a team of assistants (like a tyrant, to boot). He was obviously dealing with all sorts of flashy people, including some movie-making folks. Sitting among teenage students shouldn't make his stressed, it should be a bore for him.
But then again, this is the author who doesn't even remember what happened a chapter ago in his own series. The author has probably already forgotten the MC's whole backstory at this point.