Japanese children seem to be really mature for their age...

It really surprised me in this movie (and on other japanese movies) that young children are always surprisingly mature and self-sufficient. I wonder if it really is a cultural thing or if movies are just too idealistic.

For example, Satsuki was 10, and yet she prepared the lunch for all the family, she went to school by herself, she took care of her sister as if she was an adult, she cleaned the house and prepared the bath. Also, her reaction after hearing about the situation of her mother was really rational. In spite of this attitude, she still seemed to be enjoying her childhood at its fullest, even more like some spoiled kid would.

I have a 25 year old sister that doesn't even know how to boil water!!!

So, is there any explanation about this cultural aspect?

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EL GATO