There's scary, and then there's senselessly scary. 'Gyo' frightened me beyond belief, more than any horror movie or book I've watched or read before. Truly, this is a tererifying manga.
The story is about a couple, Tadashi and Kaori, who are visiting a remote Japanese island on holiday. However, they encounter a walking fish in their house, and this quickly grows into one of the most horrible apocalypses that anyone could have ever dreamt up.
This manga disturbed me- I highly recommend it.