Anime that has the characters leading a hidden life?

[erneiz_hyde]

Title.

Basically I have this excitement in watching scenes where the main character, the other casts, or a group is hiding something from the rest of the cast. The excitement is even greater when I try and imagine how would the rest of the cast (or the world if the scale is that big) react if the secret's out. Basically like in Heroes TV series. If the anime makes the reveal as a plot, it's OK too.

Some examples I know are like Shinichi in Detective Conan, Nura in Nurarihyon no Mago, Hei in Darker Than Black, Light in Death Note, Lelouch in Code Geass, Kenshin very early on in Rurouni Kenshin, etc etc.

Can anyone suggest any title that has this element in the story? Preferably a shounen anime with some actions in it, though I'm all ears for any genre.

[AbZeroNow]

The Haruhi Suzumiya series is seinen light novels(and anime) that has the main cast of characters keeping a very big secret from the title character. It also doesn't have a particular genre. And the narrator/protagonist is very funny and a great male lead.

[kitten320]

AnoHana - one of the characters had a huge secret
Shugo Chara - if you like fluffy stuff, one of the characters has huge secret about which you most likely won't even guess.
07-Ghost - most of the characters have hidden lives and responsibilities
Durarara! - has several characters with hidden lives
Elfen Lied - the main heroine has split personality about which main cast does not know so some secrets are there
Sengoku Otome: Momoiro Paradox - has about 2/3 characters like that.
Full Metal Panic - Main hero had a secret at the start of the series
Kaichou wa Maid-sama - one of the best examples where Misaki is hiding the fact that she works in the maiden cafe.
Kuroshitsuji 2
Madoka Magica
Mai HiME
Otome Youkai Zakuro - on lesser scale but there is one
Phantom: Requiem of the Phantom - later in the series
Romeo + Juliet
Soul Eater

[Elegance]

Well in the beginning of Trigun- The guy is a notorious outlaw but people do not know he is a very friendly guy so people do not know he is the outlaw with the biggest bounty on his head. Idk if its "hidden" but it could be up ur alley.

I second Phantom: Requiem for the phantom- Its just like Hei. Kills but acts like normal people in the real world.

[ByakuyaKuchiki]

I really love animes with this element as well. The only one that comes to mind that hasn't been mentioned so far is Gundam 00. The fact that the main character pilots one of the gundams is hidden from a few people he interacts with in his civilian life for a good part of the show. May or may not be your cup of tea though.

[Haak]

I recommend:
To Aru Majutsu no Index - Hiding his anmesia
Blue Exorcist - Hiding the fact that he's a demon.
Durarara!! - Hiding the fact that he's the leader of an infamous gang.

[kitten320]

I second Blue Exorcist, it slipped my mind.

[Kleo Scanti]

Three main characters of Ah! My Goddess! hide their true identities (being goddesses and living among humans). Though there is very little action in the series.

[SeijiSensei]

The titular character Shinkarou Kurenai lives a dangerous secret life quite divorced from the laid-back persona he uses in his high school.

In Oh! Edo Rocket, the female protagonist hides a big secret from everyone around her.

[Motcchi]

Even though it's long:
Detective Conan

[bhl88]

Nanoha and Nanoha A's

[erneiz_hyde]

oh derp, I forgot I posted this thread 2 years ago, sorry

Haruhi - Finished this already
AnoHana - Reminds me I haven't finished this one
Shugo Chara - I read the manga a bit, it's fun but not really what I'm expecting
07-Ghost - I watched this a bit, but haven't completed it.
Durarara! - Watched this already, yep, it was a blast
Elfen Lied - was one of my early titles as I began my otaku ride. I enjoyed this one.
Sengoku Otome: Momoiro Paradox - I was planning on watching this but haven't done so. I like the OST though
Full Metal Panic - I've read the manga a bit
Kaichou wa Maid-sama - yes, one of my favorite titles as well, though I haven't touched the manga
Kuroshitsuji - I watched this for a while, but haven't picked up on it again
Madoka Magica - completed
Mai HiME - completed
Otome Youkai Zakuro - never heard of this one, I'll check it out later
Phantom: Requiem of the Phantom - I played Phantom of Inferno but haven't really finished because I couldn't moonspeak yet back then. I read the wiki already though
Romeo + Juliet - completed
Soul Eater - haven't touched on this
Trigun - I've read this a bit
To Aru Majutsu no Index - one of my favorite title, but I felt the hiding aspect really wasn't all that important
Blue Exorcist - watched this for a bit, but haven't finished it.
Ah! My Goddess! - I used to collect all the localized volume of this!
Kurenai - haven't watched this
Oh! Edo Rocket - haven't watched this
Detective Conan - tl;dr I mentioned this in my OP
Nanoha and Nanoha A's - I completed all of Nanoha already

Btw, thanks for all this recommendation, but as you can see, I have a chronic condition of leaving a lot of titles in the middle. It's a combination of a lot of things so be assured that it wasn't because it was boring or bad.

This kinda reminds me, DNAngel and Ai Yori Aoshi were two non-action genre that I kinda liked which handles the hidden life part pretty well.