I love the colors placed in the background, not to dark nor too bright, and I love how you drew America and England as Ami and Yumi.(*sigh* childhood memories...good times -u-) Your art style's been developing over the months and we all come to love a budding artist who gradually blossoms as time goes on, and that's something you don't see very often. So far, the outfits are accurate as well as the characters.
Might I suggest darkening up Iggy's hair? Other than that, It's really cute and really well done.