Feel kinda bad for Ryuka. I think she's right, he really would have probably fallen for whoever confessed first, she just missed her chance. Maybe it's childish of me but I personally would have preferred it not shown her moving on and dating some random guy we never met in the time skip, for some reason it gives me a sharp pain in my heart similar to when I read NTR
Also have a hard time believing he was able to overwrite his feeling of her being his sister (who he lived with since he had memories basically) in a short one month .
This is one of those times that a true harem may have been a better option