Honestly, the age gap doesn't bother all that much since they're expected to live over 200 years. My problem is the fact that she's his "adoptive daughter", and Falco repeatedly brings it up. I get where Shou's feelings would've come from since, by all means, she's an adult and she's starting her new life with the understanding that she is an adult. Not to mention that the community she's in has such a different understanding of parental relationship than her previous community.
But she herself says she will live and act as a 12 year old.
Though i dont know much about whats happening since I only read the latest ch after the longest time.
as soon as I saw who was going to be the ml, I dropped it immediately.. what's wrong with the author?!