The title of this picture was "The Club's Princess Was Made the Flashy Senpai's Plaything". In otaku circles, "Club Princess" is the title given to a club's single female member and there's usually an unspoken rule among the male members that no one is allowed to date her, either for fear of driving her away or because it would cause unneeded drama in the group. Most of them would probably develop crushes on her though, seeing as she's probably the one member of the opposite sex that they can relate to. Others might see her as a daughter figure - someone to be protected. So this in all likelihood counts as NTR, especially since "the flashy sempai" is a common NTR antagonist.
Also, I don't think the blonde girl is the same character as the gyaru from the 100 days pic. Her hair is styled slightly different and she has pink tips. Plus these characters are probably in college given the lack of uniform. I don't think it makes much sense story-wise either. (EDIT: The author has confirmed on twitter that this is a separate work)
last edited at Jan 20, 2021 5:18PM