The appeal lies in its combination of emotional depth and thrilling plot. It makes you feel like you're on the journey with the characters. The vivid descriptions and unexpected twists keep you engaged throughout.
Friendship is a very common theme. Just like in the original anime, fanfictions often explore the deep bonds between the main characters. They show how the girls support each other through different challenges.
I haven't come across anything like that. It's a very unique and perhaps even far-fetched idea that doesn't have much precedent in the world of stories. Maybe someone could come up with a creative take on it in the future, but as of now, I doubt it exists.
It depends on personal preference. Some people like the manga for its original details, while others enjoy the anime for the dynamic visuals and sounds.
Another theme is about chasing dreams. They all have the dream of going to Antarctica, and they face various difficulties but still strive for it. It shows the power of having a goal and not giving up on it easily.
It has a compelling story with deep character development and a sense of adventure. The settings are vividly described, making you feel like you're on the journey with the characters.