Female leads like Stella Loussier from Gundam Seed Destiny. not entirely sane and unpredictable. Preferably a romance, one where they dont end up dead. And preferably a series longer than just a couple volumes. d291p

Dean Wonderland has a entire cast of unstable people lol.

The lead girl, Shiro is either dual personality or insane and deceptive.

** [color=green]Mad people either have no sense or too many extra senses... [/color]**
[color=red]On the net, men are men, women are men and children are the FBI. =D[/color]

Mirai Nikki
Bitch is crazy.

Elfen Lied meets some of those criteria.

NHK ni Youkoso!. She may seem normal at first, but looks can be deceiving...

Check out my manga podcast:
https://youtube.com/channel/UCr0Us8mMIpX3x0pOud2AUWg

Normal City
Chise's sanity in SaiKano can get pretty questionable, though it's not a central character trait or anything.
Hitsuji no Uta

Don't go into any of these with happily-ever-after expectations though...

Read Cat Street! She's not psychopathic, but she has serious mental problems. A really good read.

Usotsuki Mi-kun to Kowareta Ma-chan Totteoki no Uso Maa chan is bat shit crazy and Mii kun has a few screw loose himself but its a very good story.

Quote from reina q

Read Cat Street! She's not psychopathic, but she has serious mental problems. A really good read.

She doesn't have mental problems; she was just traumatized by her past.

Nulla in mundo pax sincera
"Always go too far, because that's where you'll find the truth." - Albert Camus

Many thanks.

I second Mirai Nikki.

Alice came to a fork in the road.
"Which road do I take?" she asked.
"Where do you want to go?" responded the Cheshire cat.
"I don't know," Alice answered.
"Then," said the cat, "it doesn't matter."
~Lewis Carroll, Alice in Wonderland

Anne Freaks is a little short, being only 4 volumes long, but the main female is definitely unstable, more like deranged and psychopathic. I suppose there was some romance, though it certainly doesn't make you feel very warm and happy...

I'm not sure if that was quite what you were looking for, but worth a shot.

mentally unstable female lead = yuno from mirai nikki
(i am quite stable, though)

grammar mistake is intentional, grammar nazis need their entertainment.

If you want lesser-known manga I do recommend Coelacanth. the protagonist isn't really mentally unstable (like on the verge of having a panic attack at any moment) but she does hallucinate talking sheep, also there is some romance.

Or even Doll Star would be a good read. At first it seems like the protagonist is just a strange girl, but as the story goes on she becomes more noticeably mentally unstable, there is a degree of supernatural events in the story.

But they are only two volumes and fully scanlated so you can get through them pretty quickly.

I second Doll Star. It was a good manga thats goes by too fast.

well i never fnished NHK, cz of me, not them xD
i do she was a bit wacko hahhahaha
it was still good so i second it

** "It's so warm that, Before the snow has a chance to stick, He melts it for me." **