This is now too far to get into a happy ending. I braced myself for a great tragedy here. While I don't want any of the MCs, SCs to be killed anymore, even Eren. But I think it's unavoidable that some of them will be gone.
Either sis is thirsty af or there had an arranged marriage. Anyway, I kinda want them to be just friends, if they date, it'd feel like Tarou would just be a mere look-alike replacement
Now, this makes me want to find a boyfriend