Never heard her Jap voice. But i'll agree to some extent about the Dub. Same with pokemon & Lillie. They should have casted someone else to play her. I think the actor in Rosario Vampire who played the girl with the Blue Hair could have been a better choice. Or even Tara Strong. They could have given her a more Teenagers voice
Now that you mentioned Akiza, does the sane actor voice Sera & Akiza? They do sound a lot like. To the person above: Too bad it's not for babies. The majority of fans are adults by now. I should check the sub.