Nanashi: Nakushita Nani ka no Sagashikata  

ナナシ　～ナくしたナにかのさがシかた～

The manga adapts Harumi Fujino's "Nanashi Series" online occult horror stories. The stories center on the protagonist Haru (a pseudonym for the author), and his friend Kyousuke "Nanashi" Nanashima, who possesses strange powers.(Source: ANN)