>>534359562
Yuzu is smart and can code, so she's fine. Even Sumire has displayed competence with stats
Explaining the twins and Mirai is where we have nothing but headcanon and baseless conjecture to go on. Maybe it's that trope where a dumbass studies really hard to get into a good school, and barely manages it. And even that is assuming there's a strict entrance exam or that there aren't sports(combat) scholarships to explain Karin
Nothing to go on at the moment