Are manga and anime the same thing?
Onmyō Taisenki
Even when the story of the Manga and Anime appears to be in the same universe there are some factual differences in the world of the anime and manga.
In the manga the names of the shikigamis are created by their Toujinshi at the time of the contract and in the anime the names of the shikigamis are always the same. For example, in the manga the name of the shikigami that once made a contract with Monju is revealed to be "Byakko no Akatsuki", and then it's revealed that is in fact the same shikigami as "Byakko no Kogenta", and the name Kogenta is the name that Yakumo gave him. In contrast the anime reveals that the name of Byakko no Kogenta has been always the same, as is revealed in the anime when the story of the contract between Byakko no Kogenta and Raihou is told. 
Also, in the manga, there are no factions between the Toujinshi, and every Toujinshi is independent.
Even when in the anime almost every Toujinshi uses a Drive, in the manga almost every Toujinshi uses a Toujinki, with the exception of Yakumo who gets his Zero Drive from the Naraku in the middle of Volume 2 in order to save Kogenta because Yakumo's Toujinki is destroyed, and Tsukuyomi that summons his shikigami with Toujin-fu.
It also is revealed in the manga that the Drive is in fact a Toujinki prototype.
In the anime when the Toujinshi shikigami is defeated the Toujinshi loses his/her memories as Toujinshi and he/she can no longer be a Toujinshi. In the manga the only consequence of a Shikigami defeat is that the Toujinshi can no longer make a contract with that shikigami.
Bishōnen
"Bishōjo" ('beautiful girl') is often mistakenly considered a parallel of "bishōnen", because of the similar construction of the terms. There are major differences between the two aesthetics. The "bishōjo" aesthetic is aimed at a male audience, and is typically centered on young girls, drawn in a cute, pretty style; and "bishōnen" is aimed at a female audience, centered on teenage boys, and drawn elegantly. Another common mistake is assuming that the female characters in "bishōnen" manga and anime are bishōjo. In truth, female characters in "bishōnen" manga are very different from those in "bishōjo"; "bishōjo" females are usually more petite and drawn in a style that is cute rather than beautiful, whereas "bishōnen" females exhibit the long limbs and elegance of the "bishōnen" themselves.