Sekigan no Shounen: Occult Maiden - Kage Shou

Kasamatsu Tae led a normal, high school girl's life with her best friend. One day, she wakes up in a hospital bed with no recollection of how or why she got there. Classmates from her school inform her that Tae's best friend Michan is now dead. Tae's normal life comes to an abrupt end as she begins to understand the supernatural and demonic beings around her. Tae now has to make the decision to either forget it all, including the death of her friend, or use her newly found ability to "see" and fight with the "Futsumashi" against these demons.

(Source: MangaHelpers)