Kure-nai - 12 episodes from Brains Base
Kure-nai follows the life of high school student Shinkurou Kurenai. Shinkurou has a rather unique job as a dispute mediator for a woman named Benika. This basically means that he goes on odd jobs for her where he inevitably ends up getting into brutal fights. Despite his appearance, he is an excellent fighter, and has studied a particular and unique fighting style developed by the Houzuki family. An orphan whose parents died in a terrorist attack, Shinkurou devotes his life to Benika, the woman who rescued him. Her trust in him leads her to give him her biggest job yet - protecting a 7 year old girl named Murasaki Kuhouin.
But Murasaki is no ordinary girl. She is a woman of the Kuhouins, a very prestigious family line with a very dark secret. The Kuhouin family is entirely pure blooded as a result of incestuous inbreeding. The women in the family are forced to live in the Inner Sanctum and are not allowed access to the "outside" from the moment they are born until the day they die. When they reach a certain age (around 14 or 15), they are forced to breed with their own brothers to produce children. The men of the family in turn marry women outside of the family, but they do not have children with them. Instead the women they marry raise the Kuhouin children as their own. For all purposes, any woman born into the family does not exist, so that they keep their way of life a secret.
Murasaki's real mother, Souju, asked Benika (who had worked for the family) to take Murasaki and show her the outside world so that she could discover what it means to love and be loved, and to have her own will. When Souju committed suicide, Benika made good on her promise and kidnapped Murasaki, then turned her over to Shinkurou for protection. Shinkurou is not only meant to protect her, however, but to show her love and give her precious memories. Of course, the Kuhouins will not just let their only current daughter leave. The family is dangerous, and Shinkurou will be harshly tested during this job. He is not alone, however; Benika's subordinate Yayoi is keeping an eye on them, and his two female neighbors, Tamaki and Yamie, help him show Murasaki what a world away from the Kuhouins can be like.
It's a very sad, but at the same time a very charming story. The relationship that develops between Shinkurou and Murasaki is innocent and precious, as he teaches her what it means to live a normal life. She is remarkably adept for a 7 year old, and her initial shock at having to live in a tiny one room apartment with no servants quickly makes way for a mature understanding of the world that only a child could have.
There's a good amount of action in the show, because even though his main task it watching over Murasaki, Shinkurou still has other jobs to attend to. We see a darker side of him that manifests when he lets himself go during a fight. He has a weapon, a horn, that he has put into himself in an effort to become stronger (it pops out of his forearm like a bone), but he tries not to use it because he realizes that he needs to become stronger on his own. His selective use of this ability is rather strange, however, as he seems to use it quite often when it is not necessary, and never when it truly is (like when protecting Murasaki, though it's possible he simply does not want her to see the monster he becomes).
The animation is excellent. I was particularly taken with the animation of the female characters' hair. I'm sure that seems like a strange thing to take note of, but if you watch the show, you'll see the way it falls around their faces and shoulders; it's quite beautiful. The opening animation is adorable, using very stylized and artful depictions of the characters (they sort of look like cardboard cut outs or paper dolls). I like the ending song ("Crossing Day" by Ryoko Shintani for the first few half of the series) the best, but the opening is also good ("Love Jump" by Minami Kuribayashi). It's a short series, and it's definitely worth checking out.
The show aired in the 2008 spring season, from April through June.