Cute picture, I wish Momo was in the middle. Excuse me..did you just say rightful? Sorry, but when it comes to Momo and Airi..well..if you knew me, you'd know what would happen.. (I'm kidding xD)
I won't argue about who's best because I love them all. But... I do think that their formation looks more balanced with Momo in the middle. Simply because she is smaller than the others. But they are all adoorable (*v*)/