In the case of élDLIVE and Reborn, I especially like to rant about the differences in our early introductions to Sonokata and Kyouko.
So Reborn isn't exactly bursting with female characters, and the ones present tend to play a very minor (and uninformed) role. Because of that, it isn't really fair to compare Sonokata to Kyouko, whom we rarely see and whose entire character, as presented to us, seems to be based around the idea that she is cute and friendly, and whose entire role in the manga is as the love interest to Tsuna. After all, Sonokata is a primary character in élDLIVE and a full participant in all the action, which is something that not even Chrome managed to achieve in Reborn (one of my pet-peeves about Reborn was that anything Chrome did that might seem cool or powerful was instantly explained away as, "But it was actually Mukuro all along!"). Not only does Sonokata appear with almost as much frequency as main protagonist Kokonose Chuuta, but she is displayed as being better than him at basically everything, including but not limited to: fighting, that one thing that female characters always sucked at in Reborn.
So it isn't a personality comparison between Sonokata and Kyouko that I intend to rant about right now (except I think I just did), it's a comparison of our introduction to the two characters.
Sasagawa Kyouko: "Her innocent smile is the best!"
So when we meet Kyouko, Tsuna has already known (and been crushing on) her for some time. He knows that she is sweet and friendly to everyone. He tells us that she is "cute" and has a "cute" personality, and that is something that never really changes. Which, okay. Despite the fact that I have major issues with how the word "cute," is used, the bottom line is that Kyouko is a nice person, and that's fine.
Our very first introduction to Sonokata is pretty similar, really. Chuuta informs us that he hasn't spoken to her yet, but that she's very cute and probably has a very cute personality, too. Sounds familiar.
And then Chuuta has his first (one-sided) conversation with Sonokata:
"You're the lowest of perverted boys. Please die without leaving behind a trace."
"Wha--She said 'die'..... Eh..." 'There's a huge gap between her face and her words!'
...And his partially-formed crush, which was so reminiscent of Tsuna's more established crush on Kyouko, withers into dust. Okay, yes, I know, this doesn't change the obligatory romance that will undoubtedly follow, but it was still kind of amazing to me that Amano (in true Amano fashion) led the reader down a path of expectation that she herself formed in a previous work and then switched it up. This is one of the reasons I love Amano.
Chuuta's new opinion of Sonokata:
'Sonokata Misuzu--a demon wearing an angel's skin!!'
This opinion of Chuuta's has prevailed throughout the early chapters so far, largely because every time Sonokata does something that impresses Chuuta to his very core (see: awesome fighting skills), she punctuates it with an insult directed at him, and often also includes a polite suggestion that he die or disappear without leaving a trace.
His most repeated appraisal of Sonokata seems to be:
'Anyway, Sonokata's personality really isn't cute.'
Again with the "cute," right? But I still like that he seems to be focusing more on the who than the how she looks, now.
I haven't read very far yet, it's true, and Sonokata could still devolve into an empty, weak, boring character (in fact, my frequently-seen-in-manga senses identify foreshadowing in that direction), but I really, really hope that whatever changes to her character come only help to round her out, not flatten her.