Her little sister always such an angry look on her face, is it wrong that I find that super cute?
@breizh
She's one of the best in her class for both sports and academics, and she did took care of her little brother by getting him to sleep. So it's all good. But I get your point, her little sister could be more relaxed if she helped more at home.
@TaintedAardvark Nah, she's sleeping every time we see her do so because she wants to. Take the drowsiness after lunch period part of things here, that's the same for the other students. She's just better at sneaky naps. Lazing around on the weekend like we saw here? Habit she formed with her dad. Now she's corrupting the younger brother, so the cycle continues.
@Glomoro
Nah it's pretty clear that she gets insanely tired with little to no stimulation or exhaustion. She can't stop herself from falling asleep even in uncomfortable situations. She's got narcolepsy.
@TaintedAardvark She's probably not narcoleptic just glancing at pages about it via Google. There are other sleep disorders that hit a little closer but this is clearly lacking the right features for narcolepsy. Either way it's a character, not a real human being in the real world. Are you going to tell me big eaters in other manga and anime just have a tapeworm or something? No, it's a tacked on character trait.
@Glomoro
Sleep is a big part of her character. Her whole character revolves around it. It's not unreasonable to say she has a condition which makes her sleep, or sleep easily. Maybe she doesn't but signs point to her having it.
Reading, though, yeah another sleep condition sounds more plausible. I think it'd be interesting to explore the possibility of her having something than just chalking it up to "She's tired because it's quirky!"