Samurai Deeper Kyo is a story of two men in one body - the humble, polite Mibu Kyoshiro and the legendary samurai Onime-no-Kyo, who has a price on his head. Consequently, Mibu Kyoshiro is captured for having an uncanny resemblance to the samurai. As the story of SDK progresses, we learn more about the two unique souls that inhabit the same body.
An organization known to the dark side of the world as Chronos claims to desire world peace, employing the top thirteen assassins in the world known as 'Erasers.' They each have a weapon customized to fit their style, all made out of orichalcum ore, the strongest material available on Earth. Number 13, Train Heartnet (codenamed Black Cat) is the most famous and revered of the thirteen Chronos numbers, but in the light of a tragic event he has come to question his path in life. Together with Sven Vollfied, a struggling bounty hunter and a living weapon named Eve, Train takes up a job as a bounty hunter - all the while running from the other Erasers and Creed Diskenth, a crazed man whom wants him to join the Apostles of the Stars, a group made to destroy Chronos.
In the time of the Vietnam War, an American military base in Japan is plagued with a rash of killings whose assailant is unknown. Enter Saya, a mysterious young woman who happens to be the last of the vampire race, and has been charged by her government agency employer to investigate the sinister killings. With demons and creatures abounding, Saya must infiltrate a school to put a stop to the bloodshed -- unless the monsters get to her first...
In times of olde, humans live in constant fear of demons known as yoma. These vicious creatures can take the appearance and memories of humans they have devoured, thus blending into society as they freely feast on human flesh. The key to stopping the yoma lies with the tolerated yet feared Claymores - women who are half-demon, half-human, and fully fated to become the demons that they hunt. Meanwhile, in a village, the young Raki has been banished; his only crime was losing his family to the yoma. Raki is drawn to a Claymore named Clare, and together their journey begins. While Clare fights the yoma plaguing the land, can Raki help her in her struggle to retain her humanity?
Both of this anime are about swordsmen (and swordwomen?) doing their worst, both are about killing people which eventually turn to monsters, and about killing those monsters too. Both are aching for some good side stories, and both are in need of a better character development. But, then again, if you are in need of your weekly dose of sword-flashing/monster-killing/mind-relaxing anime both of these will do. Claymore beeing a bit better in my humble opinion.
For Niwa Daisuke, turning 14 should be accompanied by romance and the promise of new adventures into adulthood, but instead comes with a surprising revelation: all male children of the Niwa's bloodline inherit the powers (alter ego) of Dark, a phantom thief, upon their 14th birthday! Now, in addition to his ever-present quest to win the heart of his childhood friend Risa, Daisuke must commit acts of thievery (with his doppelganger Dark controlling his body), to steal mysterious pieces of art for unknown purposes. For Daisuke, his growing pains are just beginning!
For Kouta and Yuka, finding the bloody naked young girl on the beach would change their lives forever, for better or for worse. Unable to speak or function as a normal human being, she is named Nyu by the duo, and taken into their home in an effort to save her. But what neither teenager knows is that this innocent young girl is actually a killing machine -- an experiment gone terribly wrong -- and it is only a matter of time before the murderer in her awakens again...
Though Elfen Lied and Samurai Deeper Kyo take place in different settings, both have a main character who switches between an innocent and extremely violent personality. The struggles the main characters face with their different personalities create a fascinating texture in both of these anime.