I'm looking for a manga which has character who is similar to Reiji Arima, from Kare Kano.
Reiji's an intense guy, with a crazy personality to match his genius and good looks and he definitely is one of my all time favorite characters.

Is there another such a guy in the manga world?

Rei Kashino from MARS would be an excellent example.

Absolutely love Kareshi Kanojo no Jijou too! I can't believe he hold his feelings up for 1 year! ><

Not sure it fits but:
J from 100% Perfect Girl
Se-Joon from Flowers of Evil
Cain from Hakushaku Cain Series + God Child - Cain experienced a dark past too
Ren from Skip Beat! - I'm surprised at how Ren hides his feelings, it's just too good!

"A Lady Needs Time To Prepare. Even If It Takes A Year, A Gentlemen Must Wait." ~ Wilhelm Mölders(Emma)

Thanks for the suggestions, but I've already read all of em, except for 100% Perfect Girl
All of the characters surely are angsty, but I'm looking for a free-spirit male, who has a dark past yet a compelling personality(and it would be like a cherry on top, if he is Bi, though I'm NOT looking for Yaoi) . Cain is probably closest to what I wanted, but I've already read the manga.

More Recs Please? :S

Welcome! 🙂 Hmm... I see.
How about:
Fullmetal Alchemist
D.Gray-man
Pandora Hearts

Sorry if it wasn't helping!

"A Lady Needs Time To Prepare. Even If It Takes A Year, A Gentlemen Must Wait." ~ Wilhelm Mölders(Emma)

Not sure I get the idea, but maybe characters like
Hyobu - Zettai Karen Children
Tomoe - Kamisama Hajimashita,
Ren/ Shion - Please Save My Earth,
Matoba - Natsume Yuujinchou (more or less side character)
Akabane - Get backers
Both brothers - The One
several characters - Princess

You may also check:
Gakuen Alice
Akatsuki no Yona
Magico - the brother in latter chapters
Reimei no Arcana
Aphorism
Pale horse
Majin Tantei Nougami Neuro
Ludwig Kakumei

I hope something is to your liking 🙂

Tomoe of the past from kamisama might fit the bill to some degree. And so does the fire dragon from Akatsuki no Yona. Have already read the rest, except for Please Save my Earth and Pale horse. Will check them out, thanks!

@anngeelaah, It's alright! thanks again!

More recs anyone?
😕

How about Lingyu from Scarlet Palace? He is pretty free spirited but has a dark past and can be intense at time. The king is definitely intense and cold.

Thanks, will check scarlet palace out! 😃

Any more suggestions? Anyone? desperately pleads

Anotsu Kagehisa from Blade of the Immortal is a genius with his skills, is a looker and has a crazy goal in life!

Definitely Oboreru Knife they even shared similar past, and male lead from Beauty is the Beast also gives me the same vibe (although he's less damaged). I know this thread is already old but as a fan of Reiji Arima I feel obliged to put this recommendation for anyone stumbled upon this thread (like me).

DONDAKEE!!