So yeah, i'm looking for a manga (or anime, that's fine too) where either the main character or a side-character fakes being weak, but in fact being strong. Could be some sports manga, fantasy manga, fighting manga, anything as long as it fullfills that one criteria
And to clear up any misunderstandings i'm not looking for one where the character starts out weak and gets stronger (hajime no ippo etc).
If i were to give an example, then maybe Nijima from History's strongest disciple kenichi. They're hinting that he's strong (or teasing lol) with his footwork and dodging some punch, sneaking etc. Though just that either out-of-view or actually in the manga he'd totally go clean up or somethng.
Or maybe something like a guy getting picked on in school, acting weak. Then during night or during class time he's badass
I've been searching for over a year for something like this that i really like, but i still havent found anything real good, was hoping i could get some help here.
Sorry for the wall of text btw
Well, i hope you get the picture and i'm looking forward to an answer.

Superior
Gokusen
Red lion



________________
（・◇・）/~~~ ♥

I second that. Also:
Matsuri Special - female lead
Change 2!! and W Change!! - male lead when he takes off his glasses (though the female lead takes most of the spotlight)
Oresama Teacher - female lead
Yankee-kun to Megane-chan - Adachi
Change 123 - sort of

Chrome Shelled Regios: Missing Mail. I refer to the manga as 'Chrome Shelled Regios: Shoujo Mail' since it reads as such, but if you want a more shounen feel, read the novel or watch the anime.

Sayabito.

If you don't mind shoujo, I second Oresama Teacher.

Another perhaps more shojo-ish one:

Yankee-kun to Megane-chan

Though the faking being weak does slowly come off.

Otherwise I third Superior

Holyland guy gets picked on at school but is an animal on the streets

second oresama teacher, it is amazing!

Zippy Ziggy - female lead
History's Strongest Disciple Kenichi - Miu

Edit: I didn't notice that you already mentioned History's Strongest Disciple Kenichi...

i second this

and if you dont mind violence, gore and nudity...try Koroshiya 1 ichi is a wimp and gets picked on a lot but the minute he breaks into tears he turns into a killing machine

Koroshiya 1 - The main protagonist looks like a wimp, but it's really strong.

I'm pretty sure you've read this, but Fullmetal Alchemist fits.
The main in Trinity Blood is like this for a while.
The servants in Black Butler.
Hmm.. odd example, but in the Ruby/Sapphire chapter, this fits in Pokemon Special.
Sorry if they don't really fit your request.

I agree with all those who said Gokusen.

Thanks for all the replies guys (and gals)

Elfen lied
I'm pretty sure one of the evolving girls does it initially to stall her testing or whatever.

There's a part like that in Trace it's a webtoon.
But he doesn't really 'fake' it, rather he just hides it due to the consequences of his ability.