The pace was too fast for my taste.
The friend part was great because she was in shock when she refused her help and we could understand how the protagonist felt at that moment (In disbelief). But I would prefer if we as the viewer were showed step by step the girl seeing her Sensei and friend being molested until they start enjoying the act of molestation preparing us for her eventual break down when the same thing start happening to her.
However this isn’t that kind of H-manga. So it was a meh chapter…