Maiku Kamishiro's past has always been somewhat of a mystery to him. The only clue he has to who his family might be is an old photograph showing two young children, a boy and a girl, playing in a small pool outside of a blue house. In an attempt to find his family, he moves to this blue house and begins working as a programmer. He's living a comfortable life until the day two very different girls show up at his door, both in possession of the same photograph, and both claiming to be his twin. With no way to prove who is a relative and who is a stranger, Maiku allows both girls to move in with him until they know for sure. 

(Source: ANN)

The "Noblesse" Cadis Etrama di Raizel, also known as "Rai," is enrolled in Ye Ran High School by his servant Frankenstein to stay hidden from the sights of the Union, a mysterious organization out for Rai's blood. Rai commences his life as a student, making himself familiar with his classmates and the daily activities of humans. However, his new life is far from peaceful, and Rai is soon forced to save his new friends from the hands of the Union that had abducted them. Meanwhile, M-21—a Union agent gone rogue during Rai's rescue operation—joins the Ye Ran High School security staff after a proposition by the school's director, who happens to be none other than Frankenstein himself. On the surface, M-21 is a prim and proper employee, but in truth he is shackled by his former ties to the Union and the inevitable consequences of betraying the organization. To further complicate matters, Nobles Regis K. Landegre and Seira J. Loyard enroll in the same school to investigate the Noblesse. While the Union conducts a manhunt for M-21 to extract clues regarding their missing agents, Rai is forced to keep his identity hidden while protecting all that he holds dear. [Written by MAL Rewrite]

Phantoms: supernatural entities such as ghosts or youkai that, until recently, were thought to be superstition. However, when a virus that infects the brain spreads throughout society, people's perception of the world changes as the mythical beings are revealed to have been living alongside humanity the entire time. This virus has also affected those of the next generation significantly, allowing them to develop special abilities that they can use to fight against dangerous phantoms. Haruhiko Ichijou and Mai Kawakami are two of those that were granted such power as Haruhiko wields the ability to summon and seal phantoms through drawings while Mai imbues the power of the elements into martial arts. Together, along with the friendly phantom Ruru, they form Team E of Hosea Academy which is dedicated to dealing with these often mischievous beings. In a world where the real and surreal intertwine, Musaigen no Phantom World follows the adventures of a group of friends as they handle the everyday troubles caused by phantoms. [Written by MAL Rewrite]

In the world of Loveless, each person is born with cat ears and a tail, which disappear only if that person engages in a sexual intercourse. Because of this, they have come to symbolize virginity and innocence. Additionally, fighting is only done by "fighting pairs" or couples, where one is known as the Sacrifice and the other as the Fighter. The first receives the damage while the latter attacks. Ritsuka Aoyagi is a 12-year-old boy, who for some unknown reason suffers from amnesia. His brother got killed recently, and as if his life has not been hard enough lately, on his first day at the new school he gets approached by a stranger called Agatsuma Soubi, who claims to have known his late brother. Ritsuka finds out that Agatsuma and his brother used to be a fighting pair, and that Agatsuma has inherited Ritsuga now that his brother is gone. Together, they try to find the truth behind his brother's death and the organization known as the "Seven Moons," which may have been responsible for it. All the while, it seems that Ritsuka and Agatsuma are becoming closer than they intended to be…