[Sashimister]

This proves once again that you should never learn Japanese from anime. We. the real people, simply don't talk like anime characters.

Originally Posted by DewarHolmes

I was watching Ponyo in Japanese yesterday and I noticed that Sosuke + his mom call his dad by name （こいち）, instead of saying おとうさん or ちち.

That would be pretty rare but still possible. But you will never use ちち there, period. You use it to talk to another person outside your family about your father.

By the same token, Sosuke calls his mom りさ instead of おかあさん or はは. I'm not positive, but he might have referred to himself by name at one point as well.

That would be super-rare to nearly impossible. Never seen a family like that in my rather long life in Japan. Again, はは is utterly impossible to begin with.

PS.Also-perhaps because of their closeness-he never says りささんorこいちさん.

Impossible. You don't address your parents "Mr. ~~" or "Mrs. ~~", do you?