Well this got cliched quickly. Wait how does the sister not remember her sister hanging out with him? Did she like not introduce her friends to the family? And their other mutual friend did remember them together and they said both sisters and the MC went to the same middle school. Plus I feel like the story about a guy getting a concussion and losing his memory in middle school would make the paper with a picture. So is the GF twin secretly the one that’s manipulative and knowingly steals her sister’s crush (I can get behind that twist) Also can circle back to the memory loss? Because I don’t remember him EVER mentioning having forgotten anything and he’s never seemed to be confused about his past before. So the memory loss only affected his memories with the other sister? In which case that’s really selective and would mean she specifically caused him some trauma (which would she is bad for him). I feel like the author should have gone with The even more clichéd shared childhood with the MC just not putting 2 and 2 together or forgetting because it was 10+ years ago, because this weird memory loss is really hard to swallow.