Toaru Majutsu no Index II

The setting takes place inside a futuristic city where magic and science powers coexist. The male leads have a large female harem, probably because of the male leads' habit of always helping damsels in distress, with no regard to their own lives. Both male leads' signature finishing move is to punch their opponents in an exaggerated manner. 

Both involved in religious organizations with a supernatural twist. Action scenes are quite similar, as well. Ao no Exorcist focuses on demons and exorcists (obviously; just as the title suggests), while To Aru Majutsu no Index deals with espers and magicians, as well as saints and priests with powers. 

Other than the first part, Toaru Majutsu no Index II constantly made me think of Kyoukaisenjou no Horizon. - Several inconnected storylines (at least I didn't see the connections, or an overall storyline at all) -> I did not get what both series were actually about - Lots of characters (which made me constantly wonder who is who and which purpose does he/she serve?) -> could not really connect to any character, not even the mains - Lots of techno babble (which I did not understand) - Lots of sermons (which I found annoying) - Comedy in each epiosode (which I found lame) - Some great action scenes, with interesting skills and weapons (which made me keep watching both titles) So if you like series with convoluted storylines, lots of drivel, many insignificant characters, unfunny comedy and cool action scenes, both titles may be for you. read more 

The strongest resemblance between the two reside in the fashion in which the protagonist build his harem, literally through throwing their lives away to save girls who they just met. Both MCs, though without strong ability power, have a strong sense of justice that can not be swayed no matter what. Of course, the main girl in each arc inevitably end up falling in love with our hero. Furthermore, these anime both revolve around supernatural occurrences. While Toaru is based on more of a magic vs. science world, Bakemonogatari is a reinvention of Japanese myths.  

Both shows use outlandish contrivances that evoke strong emotion. While I find their ridiculous inventions equally bizarre, the frequency differs. So does the emotion I get. With Index II, almost the entire show had me falling off my chair laughing. Owari no Seraph occasionally frustrated me, inciting me to shout things like "who came up with that!?!?!!" Still, I think people who enjoy all the crazy, random, stupid crap the anime industry comes up with will like both series.  

Both anime show us story about big city life. There are few organisations fighting with each other and on the other side we can see daily routine of quite untypical teenagers. Both series have a large number of heroes. Each of them has its own personality, individual traits, habits and vices.Their fate is often intertwined with each other, complicating the whole story-line. Consummate sociologist will definetly find himself in both stories. However, the plot in Durarara!! is conducted in more mature way. 

Both shows possess a similar tone and animation style. Just as Densetsu no Yuusha no Densetsu can quickly transition from silly and fun to serious and bloody, To Aru Majutsu no Index also does the same by looking like a seemingly kiddy moe series but in fact is a great violent show that would even include male to female violence. In addition, the way how both shows get bloody are the same by the additional usage of shadow background. 

Leader of Amakusa (In the first arc) is exactly like Mugen. 

Stern Bild and Academy City are both similar in that they are technologically advanced cities home to millions of people, a number of whom have special powers. In Index they are students going though the Power Curriculum Program in order to become espers artificially. In T&B they are normal citizens with a certain genetic mutation that gives them special powers; several of these citizens use their powers for good and become Heroes. In the case of both series, those with powers can turn toward good or evil depending on their situation and beliefs, and at times are considered by others to be monstrous due to being different from normal humans. read more