Unless Kud Wafter is a story about Kud and Riki blowing up their school and living somewhere far away on their own, I don’t see how there’s ‘no reason’ for Kud to act funny. Being the funny foreign girl, or a mascot is not her role within the Little Busters group, but at school. So as long as there’s high schoolers around, she’ll keep acting. That aside, being kawaii is a basic function of a mascot.
Even if, in Kud wafter, she would have ‘no reason’ to act like that, I doubt that the game producers could just cut out a part of her character concept. After all, I’m pretty sure many Kud fans are only in the boat because she’s a cute wafu loli with a high-pitched voice (just listen to that opening, man. And people are digging that stuff…). They wouldn’t remove something that sells well even if they could explain it properly ingame.
What if Riki really liked the “wafu” part? Just the thought he might have would be reason enough to keep it around.
And lastly, even if she’s not behaving like a kid on purpose, it’s still not an actual mental defect. People not acting their age isn’t all that uncommon.
It’s not that I don’t get where you’re coming from, but I do find it rash to question Kud’s sanity over such a minor quirk.
Elaborate, please. What exactly is so weird about her?
Sayuri is mature enough to approach a social reject unbiased, she’s skilled at interacting with people and is knowledgeable in social and political matters. Most high schoolers look like driveling brats in comparison.