How do you even find Nessa or Sonia?
They aren't located where it says they are....
What's the point in adding scenes for them if you can't interact with them.
Edit:
So I guess you can only unlock them through advancement in the "story".
I will second most folks' opinions. The game needs more pokemon H events. Just giving every character the same interactions makes it feel very shallow and pointless. A focus on variety and quality as opposed to copy/pasting the same thing for every character would better received. IMO