Darker than Black

In Tokyo, an impenetrable field known as "Hell's Gate" appeared ten years ago. At the same time, psychics who wield paranormal powers at the cost of their conscience also emerged. Hei is one of the most powerful of these psychic agents, and along with his blind associate, Yin, works for one of the many rival agencies vying to unlock the mysteries of Hell's Gate. (Source: Anime News Network)

X-Men

The X-Men are reunited following the death of a teammate, and are summoned by Charles Xavier to Japan following the abduction of Hisako Ichiki (Armor). There, they confront the U-Men, a lunatic cult that steals and transplants mutant organs to further strengthen their own army, and the battle for justice is on. (Source: Marvel)

Yozakura Quartet

When demons walk the streets, the cops need to recruit more demons! In a town where humans and demons co-exist, it takes more than a normal police force to maintain the peace. Enter the Hiizumi Life Counseling Office, a fantastic foursome of unique teenagers, each gifted with an amazing super power! Since it sometimes takes real demon-fire to fight demon fire, the first three quarters of the team aren't exactly human: Ao, a cat-eared telepath; Kotoha, a half-human conjuror; and Hime, descended from a dragon (and the town's acting mayor), all of whom also happen to be delightfully female. Rounding out the group is the token male and human, Akina, the office director and "Oyakume," capable of banishing spirits permanently (and from their point of view quite fatally) via a process called tuning. They may not look as impressive as some other superhero teams, and they certainly don't have the most dynamic name ever, but come hell hounds or high water, but they will defend their city! (Source: RightStuf)