A giant wall looms over Tokyo, shielding the city from a dangerous otherworld called the 'Hell's Gate'. Within the city, things are no less terrifying because Contractors, psychopathic killers with phenomenal powers, have started to appear. These killers are compelled to pay a price every time they use their powers, often in the form of a meaningless or painful task. As their deadly habits rack up a gruesome death toll, Kirihara Misaki and her team from the Foreign Affairs Public Security struggle to solve the cases and bring the Contractors under control. Their task is further confounded by the interference of a masked individual they title Messier Code BK201, a man with abilities that allow him to fight and defeat the Contractors. Who is this BK201? How can the Contractors be stopped permanently? And what does the appearance of the Hell's Gate mean for the people of Tokyo?
Duke Tougou - otherwise known as Golgo 13; he's loved by the ladies, hated by his enemies, is enamored with firepower, and can take out a target from several kilometers away. With an arsenal of weapons at his command, Golgo 13 is hired by a variety of people to take down hijackers and more - but he also must protect himself against those who want to take down the legend himself!
Years after having been exiled from the Kannagi household for being unable to utilize their fire magic, Kazuma returns to Japan, only to discover that the Kannagi family's very existence is threatened. Unknown to them, during his absence, he had become a Contractor and thus acquired a vast strength in wind magic. Not showing any remaining contempt for them, he offers to help solve the Kannagi household’s problems in return for large sums of money. Together with his younger brother Ren and the feisty heir to the Kannagi household, Ayano, he fights to protect those he cares about... for a price!
If you liked one, you would most likely enjoy the other, as both series have dark, powerful main characters with a mysterious past who would achieve their personal goals at the expense of others. As you watch either of these, you can see the same development of the main character into a better person.
As scientists explore a new form of energy on the moon, an experiment gone awry brings the lead scientist's life crashing to a halt. In a freak accident, his daughter Kurau is engulfed in the energy and becomes the mysterious entity known as Rynax; a pairing that endows her with new superhuman abilities and a new personality. Years later, Kurau is using her unique powers to make a living as a bounty hunter, but the corporation has not given up on this new form of energy and will stop at nothing to find her. Now, Kurau must protect not only herself, but her Rynax "pair" named Christmas, a soul mate more precious to her than life itself. Can Kurau and Christmas find peace for themselves and the Rynax?
Much like 'Darker than Black', this series stars a character with supernatural powers who longs to be with and protect someone precious to her. And to add to the similarities, Kurau also finds herself hunted by the authorities early on in the story, much like Hei.
Both series also share a sci-fi setting that features some unusual phenomenons and solid visuals and music.
The biggest difference between Kurau and DtB is that Kurau really focuses on one big storyline whereas DtB is divided into story-arcs that don't really connect to each other.
To make money, high school student Shinkurou Kurenai works for the secretive Benika as a "dispute mediator," acting to intervene in the disputes of clients – often violently. One day, Benika gives him a much different assignment: to protect Murasaki Kuhoin, a seven-year-old girl from the wealthy Kuhoin family. This turns out to be a more troublesome task than he expects, as Murasaki is spoiled, naive, and completely unaware of what life is like outside of the luxurious one she had previously. He also has no idea why Murasaki needs his protection, though he is slowly obtaining details from a well-informed classmate. Adding to his problems, Shinkurou still must continue to do his previous work for Benika and take care of his social relationships in school while protecting Murasaki, complicating his entire life. Nonetheless, as time passes, he and Murasaki grow close; however, trouble brews in the shadows as everyone - including Shinkurou - seems to be harboring secrets...
Both series have a strict and full in medias res start. No effort is taken to explain to the watcher how the world works or other unrealistic introductions like that. Both focus on deeper philosophical issues and daily life instead of spending time on a normal plot.
Both have fantastic yet relativly simple, short and brutal fight sequences with a dark and gritty artstyle
Beyond the knowledge of most people, the world contains a dark secret: of every person in the world, there exist two identical copies (called Doppeliners) with the same body and mind. Among the three, however, is distributed only a finite amount of fortune; should they ever encounter one another, the one with a smaller portion dies and the remainder is distributed until only one, the Master Root, survives. Keita Ibuki lives his day-to-day life as ignorant of this as everyone else until he stumbles upon a mysterious young girl named Kuro who explains to him these secrets of the world. Despite not wanting to have anything to do with her or the danger that inevitably seems to follow, their fates become intertwined and he finds that the Doppeliner system has more to do with his past than he realizes.
Apart from having the same feel to the animation, both of these anime have similar fight sequences with very similar styles and energy. The theme of the supernatural fighter is prevalent in both as well.