SLASH/DOG is a novel written by Ichiei Ishibumi and released on August, 2006, due to it's lack of popularity, only 1 volume was released. In 2014, Ishibumi reinstated Slash/Dog under the name "Dog God of the Fallen, Slash/Dog (堕天の狗神SLASHDOG, Daten no Inugami SLASHDOG)
Caught with a severe fever before his school trip, Tobio Ikuse, a second year high school student was forced to missed out on his school trip with his schoolmates on a luxury liner. Four days later, the news about the disappearance of the teachers and second year students from his school reaches Tobio's ears. Few months after that incident, Tobio having slowly recovered from the lost of his friends, accidentally encounters one of them again. Chasing after his missing friend, Sasaki, Tobio caught up with him but was shocked to see Sasaki with a Lizard Monster and attacked him with the monster. Cornered by the monster, Tobio is rescued by another survivor of the missing luxury liner, Natsume Minagawa. Tobio is then handed an egg by Natsume before parting ways. Later that night, Tobio found himself under attack again this time by two people with monsters, amidst all of that, out of Tobio's shadow came a Puppy who rescued him. After fending off the two monsters, Natsume once again approaches Tobio and decides to bring him to their hideout.
- Chapter 1 - Return/Attack
- Chapter 2 - Black Dog/Birth
- Chapter 3 First Part - Ally/Fourth Person (First Half)
- Chapter 3 Second Part - Ally/Fourth Person (Second Half)
- Chapter 4 - Silver Hair/Boy
- Chapter 5 - Reunion/Utsusemi
- Chapter 6 - Ice Princess/Four Fiends
- Chapter 7 - God Cutting Longinus Materializes/Canis Lykaon
- End Chapter - Five Great Families/Himejima
- Tobio Ikuse
- The main character of Slash/Dog. He is the possessor of the Longinus, Canis Lykaon.
- Sae Toujou
- Tobio's childhood friend who went missing after sea accident on their school trip inside a luxury liner.
- Natsume Minagawa
- Another survivor of the missing luxury liner like Tobio. She is the first person to teach Tobio about the Sacred Gear.
- Kouki Samejima
- A well known school delinquent, like Tobio and Natsume, Samejima is a survivor of the missing luxury liner incident.
- A magician from the organization, Grauzauberer, sent to assist Tobio. She is the possessor of the Longinus, Absolute Demise.
- The Governor General of the Fallen Angel organization, Grigori.
- Vali Lucifer
- The descendant of the Satan Lucifer and possessor of the Longinus, Divine Dividing.