Kurozuka

Kurozuka is about a 12th-century man named Minamoto no Yoshitsune (Kurou). Kurou flees into the mountains after losing to his brother Minamoto no Yoritomo, the first Shogun to rule all of Japan. History records that he committed suicide, but instead, Kurou meets a strange, beautiful woman named Kuromitsu in her mountain hermitage. Eventually, Kurou falls in love with Kuromitsu, but then realizes she conceals a dark secret. He learns that he is unable to die and continues to live for a thousand years as Japan evolves into a future society. (Source: Anime News Network)

A novel, manga, and Twelve Episode Anime by Madhouse. The anime has some truly outstanding animation and an awesome opening theme if you're willing to deal with an extraordinarily confusing plot.

Tropes:

 * Action Girl/Biker Babe: Rai of the resistance.
 * After the End: Caused by nuclear war and the ensuing nuclear winter.
 * Badass Longcoat: Arashiyama of the Red Imperial Army.
 * Cool Old Lady: Saniwa, leader of La Résistance.
 * Eerie Pale Skinned Brunette: Kuromitsu.
 * Face Heel Turn:
 * Fan Disservice: Arashiyama exposes a resistance fighter's breasts before killing her, just because he can.
 * Gainax Ending
 * Immortality: One of the main focuses of the story. Kuromitsu is type III and Kurou is type.
 * Immortality Seekers: The Red Imperial Army. They want Kuromitsu's blood because it can make them immortal, and their pursuit of her underlies the entire story.
 * Mind Screw/Jigsaw Puzzle Plot: Surrealism, flashbacks, illusions, and lack of explanation makes the plot near incomprehensible until the grand finale.
 * Narrator All Along
 * Off With His Head: Happens to several characters.
 * One Winged Angel: Arashiyama does this during his fight with Kurou.
 * Our Vampires Are Different: Kuromitsu and Kurou possess the desire
 * Rain of Blood
 * La Résistance: The Haniwa movement. Kurou helps them fight the Red Imperial Army.
 * Scenery Porn: Every other second. Yes, even the bloody parts.
 * Scenery Gorn: Every other second (The other half).
 * Super Serum: Kuromitsu's blood has this effect on a few of the people who are injected with it. The rest don't survive.
 * Super Soldiers: The field generals of the Red Imperial Army, thanks to Kuromitsu's blood. One reason the RIA is chasing Kuromitsu is so they can use her blood to make more.
 * Time Skip: The show skips thousands of years early on.
 * What Do You Mean Its Not Awesome: A number of examples, from cooking stew to throwing away a bag filled with an old man's feces.
 * Who Wants to Live Forever: Kuromitsu's immortality makes her a continual target of the Red Imperial Army.
 * Who Wants to Live Forever: Kuromitsu's immortality makes her a continual target of the Red Imperial Army.