I kinda wonder 2 things.
The transfer girl befriended the bitch, cause she fell its weird how the girl got "bullied". I could even understand it cause the class betrayed the dude more than the bitch - so like she maybe saw them as "worse" ones and befriended the bitch. She probably learned about MC from bitch herself - as hinted by the chapter. So I kinda wonder why didn't she like thanked him for helping/saving her from the fate he got? Or something.
The other thing - WTF that bitch done/was able to do to make whole class to listen to her and betray the MC? Like they were going to ignore the transfer girl just cause she asked, were so happy to not do it when MC kinda stopped the whole thing, and they instantly changed their minds and fucked over their "saviour"? Either they have no balls/brains and listen to who ever is the loudest in the class or she was some kinda rich princess who could fuck their life up if they didn't listen? But then she did nothing to them when they started ignoring her so like, this whole thing seems forced and kinda unrealistic a bit?
EDIT after reading the next chapter: Ok transfer student thanking happened, so at least that got explained. Also the "bitch" will probably end up joining the harem or at least the battle for his heart, cause its pretty visible she had and probably still has a thing for him. Just an emotionally unstable extreme tsundere of sorts?