Soremite: Soredemo Rei ga Mitemitai

Two manga authors: Ishiguro and Onodera, begin a quest to experience paranormal activity first-hand. Their adventures are chronicled in this manga, but there is a catch. Once they undeniably experience paranormal activity of any form, this series will come to an abrupt end. Their love for ghosts and demons are unmatched by their peers, but will they ever be able to encounter any?

(Source: MangaHelpers)