Jul 24, 2024
It’s pretty clear that this girl is someone he knew and was intimate with before he lost his memories. I’m not sure if she’s alive or not, but judging by what we’ve seen so far, she’s probably dead and Reiji may have abandoned her before.
That leads me to this theory (which I’m not entirely confident about):
This girl is appearing in Reiji’s dreams as a result of his subconscious guilt for abandoning her and letting her die. It appears that she wants to kill him because Reiji thinks that’s how she would feel towards him if she were still alive. He believes she would resent him and want him dead, all because of this supposed mistake he made.