Have you ever realised that sometimes Manga-ka draws their manga better as they make their series?
Try to compare a first chapter of a manga to 40th chapter of that manga. did they change? did the drawings become better, or worse, or perhaps both?
To me (as i make this topic) the obvious ones are:

Naruto
we're talking about each of the parts here.
when Naruto was little, what i could say is that the drawings are messy. and as the end of naruto/sasuke last arc, it actually got smoother.
and when he was 16 the drawings became bit better, and as of now, i realised the drawings become more bold and stronger, but there are some unwanted sfx (like, 'plick' for BOTH two eyes) occur.

Kaichou wa Maid-sama
as of current chapters, i think the drawings are becoming too stiff, although they become better, as in, become 'stronger'.

Watashi ni xx Shinasai
i don't know about this one, the first chapter's drawings are better than current chapters. some of the anatomy are a bit off '___'

so........ what are your opinions? maybe give more examples of those occurred changing in other manga? do you like the 'level up'?

yeah I agree ^^
here are some evidence I found (for Ouran High)

first Chapter:



46th Chapter:



from the 1st chapter to the 46th chapter you can see some of the character's hair or other features changed, they became more detailed and the face shapes became more softer :D
I like the art as it progresses because it looks newer and fresher (i don't know how t explain it clearer lol)
I just think that these kind of art look more modern

This is chapter 10

and this is 346

Yeah, a lot of mangaka do that. It's because they may not be sure of how they really want to draw a manga, so they will adapt until they are comfortable with the style. This is especially apparent with long running series, because the mangaka would obviously get better at drawing, or at least they'd get better funding. The first example that comes to mind is Yotsuba&!; Yotsuba's hair shrinks (this is the best I can describe it Dx), every one is drawn more stylized, and Koiwai-san starts looking cleaner in a way.

DNAngel... since it's been going on for so long. Started in 1997 and currently on hiatus with the latest volume released January 2011 (only 15 volumes so far)

Volumes 2, 5 and 13.
For comparison purposes, these are all the same character.

The character designs in Berserk changed an awful lot.
So did Sesshomaru's face in Inuyasha.
Ai Yori Aoshi had some pretty radical changes in the character design as well.
To a lesser extent, the boys of Saiyuki changed a bit after the first few volumes.

yeah naruto volume 1 is different then naruto volume 27 haha

The change in Gravitation's art from volume 1 to volume 3 is like HOLY SHIT.

This yaoi manga changed a whole lot





GodChild changed too

and Gravitation,too lazy to upload pictures >.>

Okay, I'll name a few.

Fruits Basket by Natsuki Takaya.
Her characters were more "pointy" and sharper.

Now it's more rounder, softer

Now, I was used to her other style and then it changed..lol. It didn't change for the worse, but like I said, I was used to the other style.

Ghost Hunt by Shiho Inada & Fuyumi Ono.
Also sharper

Rounder

It wasn't a huge change, but I do like the fact that Mai has better hair now. *shrugs*

KHR by Akira Amano
More weirder..

Better and more fun

In the beginning it was art I had to get used to and needed to stop thinking of Kingdom Hearts, but now.. I like it. I don't think of Sora so much anymore..lol.

Others:
Bleach (better)
Naruto (it's fine)
D.Gray-man (eh.. people are starting to look a like)
Gakuen Alice (better)
Zombie-loan (better)
Magic Touch (much better)
Happy Cafe (better)
Code Breaker (better)

Bleach, You can see the change in ichigo for sure.

Before



After


I don't know about you, but he actually looks younger and hotter after.

Ugh yeah..........I was disappointed in that change. I rather dislike the "round" style. It's just too generic. She broke her hand though. Legitimate excuse.

I personally didn't like the way fruits basket changed

The one I was thinking of soon as I seen this topic was Rosario+Vampire. The first couple of chapters its like the mangaka was trying to find his style but now I like the mangaka and hope he does more after R+V is over since his characters really do have different independent looks even for minor one time only seeing background characters.

Rosario Vampire!

Early Moka vampire


Later Moka vampire



Also, D grayman and Rurouni Kenshin had big changes as well!