Ref is a dog from Namonaki Inu No Uta.
Namonaki Inu no Uta
He met the German Shepherd John with Hidetoshi when they were in Africa. One day a lion tries to attack Ref, but John and Hideoshi stop him and decide to keep the dog and take him to Japan. After this, Ref decides to follow John for the battle against Akakabuto. Meanwhile during the battle, one of Akakabuto's minions tries to attack John, but Ref defends him and jumps on the way. Ref receives a hit and dies saving John's life.
- Some fans believe Ref is an Akita or any other of the Nihon Ken/Dog of Japan, but nothing is confirmed.