Male love interest that meets ANY of the following conditions:

• Not all there mentally / insane
• He's "bad for her," as in a destructive relationship (but not domestic violence)
• Heroine is somewhat creeped out by him or he does creepy things

The problems he causes for the heroine don't have to show up in the story, but there should be clear warning signs. Romance or reciprical feelings are not required, but it'd be nice. Must be a viable love interest though (take "viable" however you wish).

Male yanderes also fit this description, but it doesn't necessarily be that extreme (though I don't mind if it does). I have checked out EVERYTHING on this list.

===== Some manga that meet this: =====

Nejimaki Mano-san (One-shot) - The manga that inspired this post. To quote a character from the story, "Something's wrong with his head."

At one point, he was playing with some kids and wins a teddy bear as a prize. He then just tosses the bear in the river in front of the kids as if it was the a fun thing to do, without any particular malice.

Ane no Kekkon - He's a stalker and he freaks her out sometimes.
Metronome - Main guy is insane and delusional!
Cheese in the Trap - Possible sociopath.
Renai Shinjuu - Not the best story out there, but destructive relationship. This isn't really a spoiler since it happens in the first half of chapter 1, but...

he gets the girl to join him in a double suicide attempt since people are trying to tear them apart.

Aishite Kudasai, Sensei - Not right in the head. My favorite part is:

When he destroys the girl's office when he can't find her, but then sees her coat. He gets this insane happy look and starts smelling the jacket.

==== What doesn't count: =====

Tonari no Kaibutsu-kun - He's more of a socially inept and somewhat clumsy type. Yeah, yeah, he has that ONE LINE of a dangerous thought, but it's not a pattern and none of his actions head in that direction. The one line I'm referring to:

He mentions how he wants to cut off her limbs so she can't run away.

I've also seen the Dangerous Male Love Interest thread. To me, they seem more like the stereotypical bad boys from teen movies. As in, they never do anything particularly "bad" other than smoke and get into a couple of fights. If he feels guilty for the bad things he's done... he might not be what I'm looking for. If he feels bad because the heroine caught him... we might have a case here. lol.

Maybe Watashi no... Megane-kun But both are pretty creepy so it might not be what you want.

You could also check Abnormal-kei Joshi if you haven't yet. But it's a harem so the romance is kinda meh, and all MCs are pretty much crazy.

Bokura no Koi wa Shi ni Itaru Yamai no You de Is a revenge love/hate story. It definitely fits the "bad for her".

Edit : just noticed your comment about male yandere... sorry forget about 1 and 3 then.

Kare kano, 100% perfect girl, A Night of a Thousand Dreams, Destination Heaven Chronicles, Hannune Banhada! Season 1, The Snow Queen. Some may be stretching it.

“The mind is its own place, and in itself can make a heaven of hell, a hell of heaven..”
― John Milton, Paradise Lost

Maybe Ringo no Asobikata?

Recently finished up on Love at First Sight Season 2 (Hannune Banhada!). Season 2 does have someone who might be considered yandere. Maybe. At one point he

hits her (once/twice, I think), which is bit closer to domestic abuse to me (not into that).

But he really was mentally unstable, and went NUTS when he when she tried to leave. I loved that part.

He was surprisingly scary at times. Especially that moment when he "relapsed." I was like "Oooh, snaps. Something's going down!" It's a shame the series had an utterly nonsensical ending.

Also finally got around to finishing Watashi no Megane-kun. I had read it a long time ago and then there was no scanlator for a year or two... Even though it's recently completed, I had been delaying for awhile. (No reason why). Overall verdict: Not bad. I just wish there wasn't this weird emphasis on virginity and "belonging" to the first guy. Anyways, hits the obsessive love buttons, but lots of needless drama.

Other than that, I've read them all!! Lovely recommendations. For posterity's sake, here ones that met the criteria:

Bokura no Koi wa Shi ni Itaru Yamai no You de - Obsessive/manipulative male. Not right in the head for sure. Scanlations not far enough to tell if romantic in nature or just psycho, lol.
100% Perfect Girl - Possessive lover (beyond what's normal). Has some mild emotional dependency on the heroine. (He falls apart when she's not with him.) Half way through the series, he kind of loses it. Some people say he's yandere. I sort of agree, but it doesn't last long enough for me to endorse him as yandere material. (Loved this series though.)
Abnormal-kei Joshi - Yup, the guy is "not right in the head." Very cold-blooded and apathetic to everything. Technically meets the criteria, but I'm a little hard-pressed to say that he qualifies as a "love interest" since the guy is more of an object of obsession than anything else. Still, great and refreshing read.

Ones that didn't quite count:

Kare Kano - Just regular ol' possessive lover (within normal bounds). Gets "dark" at times (teen angst IMO), but nothing particularly crazy (literally and figuratively). Heroine is also super accepting and never freaked out by anything he does. (None that I can recall anyways).
A Night of a Thousand Dreams - Been awhile since I've read this, but mostly dangerous lover. I guess he had some issues, but they were never quite in the "insane" territory... Also, the main couple is a BL pairing. While I do enjoy BL, I'm kind of looking for M/F couples right now, since this kind of thing is harder to find.
Destination Heaven Chronicles - Teen "bad boy" territory. Somewhat flirty male. Not even sure if I count him as possessive. Also been awhile since I've read this, so I could be wrong.
Ringo no Asobikata - Mostly just a mysterious and teasing (potentially cruel) guy.
The Snow Queen - Just a dude angsting over a friend's death. Survior's guilt and all. The girl probably had more problems, being a spoiled rich girl, in every sense of the phrase. (I recently reread it and hated the heroine so much.) I guess you could say he's bad for in that he puts up/enables her bad behavior.

I became interested in this topic. Is there any more to the one's that already in been recommended here?

I'd say Hana yori Dango kinda fits the description. He's .. a little of both dangerous (little) and not right in the head.

@chrum
Hana Yori Dango - Technically fits, if you count that he's a spoiled rich man-child that throws slightly extreme fits. (He does have sweet moments though.)

Some others to add to this list that I've read recently:

Conflict Lovers (Chapter 4) - Male lead has slightly creepy attachment to little sister. (He's a mild yandere).
"Aishiteru", Uso Dakedo - Borderline case ("bad for her"). The manga glosses over it, but he does something that's pretty messed up when you think about it. Almost yandere logic, or just extremely possessive. Climax/ending spoiler:

He was blackmailing her. When it seemed like she might try to get along with other boys, he reveals her secret to the whole school so that he'll be the only one there for her.

Goth - No real romance, but male lead is obsessed with a girl, serial killer style (but doesn't act on it). Definitely not all there mentally.

I think the male and the female are bad for each other? Misshitsu no Rakuen
The ending kinda makes the male to have that vibe? Puzzle (MORIE Satoshi)
System of Romance

I'm sorry if it doesn't meet your criteria

[img]http://37.media.tumblr.com/tumblr_lxe0g342iH1qb4p3ko2_r1_250.gif[/img]

ooo i liked Misshitsu no Rakuen ... it was nice to see an equally dangerous female lead.

WEBTOONS ヽ( ★ω★)ノ

Korosareru nara, Isso Sakura no Ki no Shita de

just try looking in the obsessive love tag too, maybe?

hot blooded woman
Look for Oppa!

Hey so I know this is very old forum and I'm not sure if this one would apply but....I'd be happy if one of you lovely beings would try to read Hakuji to see if its your cup of tea :>?

It's borderline yandere/psychological. Also, this thread is a goldmine ;v;.

Hadashi de bara wo fume

Show princess

Soredemo sekai wa utskushii

Nanohana no Kare

Sekai no Hate

"FEED YOUR OWN EGO, I'M BUSY."

Issho ni Neyou yo

Main guy is fucked up in the head due to being able to see ghosts. You think the female lead is genuinely afraid of him, but it turns out she's just afraid of his power despite being in love with him.