If you don't know Stockholm/Lima syndrome, see Wikipedia. But basically, Stockholm is where the captured develop feelings for the capturer, and Lima is vice versa.

Now, do you know a manga with this set?
No need to be really a hostage. It could also be a case where one chara put his/her most important person in a cage-like, doesn't allow her/him to go anywhere. BUT the main reason the captured is imprisoned is because the capturer's wants the captured only for her/himself, NOT a situation where someone held as hostage and then they fall in love. I don't really care whether the captured has feelings for the capturer or not, but the capturer has to have feelings for the one captured.

Do you have a recommendation for that?
Any genre is fine. Doujinshi also fine. Oh, but:

• if yaoi, not something with too girlish boy
• no comedy
• something with angst will be very good

If I remember it right, there's a Stockholm Syndrome categories or thread, but I'm asking for something more specific...

Hehe, may I ask for your recommendation?

Definitely Haou Airen. No others come to mind atm.

its not really what your looking for but you could try Kirikagohime to Mahoutsukai, he does not have any feelings for her he just sees her as one of his objects so he keeps her locked up. though he does develops feelings for her throughout the story and becomes nicer to her.

[img]http://24.media.tumblr.com/3b280fafb72cad0f718be64368e64ca7/tumblr_myylzmuiY41rw3pzao4_250.gif[/img]
Like educational manga? take a look at Ed U. Manga's list of manga here

antique romance maybe?

[img]http://i.imgur.com/atMHiLJ.jpg[/img]

hmm how about Kimi no Knife?

[img]http://puu.sh/8KZ1O.jpg[/img]

Quote from hkanz

Definitely Haou Airen. No others come to mind atm.

I'm sorry, but after trying first volume, I can't get to like it. The story and the development of their feelings in volume one is just... not deep enough for me 😔 Thank you very much for the recommendation 🙂

Quote from Gale1

its not really what your looking for but you could try Kirikagohime to Mahoutsukai, he does not have any feelings for her he just sees her as one of his objects so he keeps her locked up. though he does develops feelings for her throughout the story and becomes nicer to her.

Quote from spazzmatron

antique romance maybe?

Quote from monkry

hmm how about Kimi no Knife?

I had read them, thank you very much for the recommendation 🙂

5-ji kara 9-ji made

not to everyone's tastes, mind. But he certainly wants to hide her from world and does lock her up..

WEBTOONS ヽ( ★ω★)ノ

How about a webtoon Abide in the Wind? It's a spoiler though (happens later at unscanlated parts) XD, and he doesn't exactly capture her, but more like keep her away from everybody attitude. Ooh, how about Flowers of Evil, again spoiler, but completed. As well as 100% Perfect Girl? A very possessive and angsty manhwa~ These reccs are unfortunately not 100% up to your request, but I believe they have a subtle Stocky Syndrome thing going on there.

I'm in idol hell T.T

Kago no Naka, maybe? 😕 No syndrome, but she does get confined. Very short story though.

My Beast - Not that many chapters scanlated, but this guy is obsessed with the girl.