Arnold

Arnold looks to be a Labrador Retriever, large and powerfully built as a watchdog should be. A deep, bleeding gash runs across his throat, the very wound that took his life and that stays with him into the afterlife.

Despite his size he is gentle toward newcomers, never menacing Rohan or Koichi, and his devotion to Reimi runs so deep that he refuses to leave her even after both have died.

Arnold guarded Reimi's home until the night Yoshikage Kira broke in and cut his throat, then strung the body from a coat hook with the neck all but severed, the blood dripping for over ten minutes before anyone realized he was dead. Trapped afterward as spirits inside a haunted alley, dog and mistress waited for someone who could hear their account and turn Kira in before he claimed more victims.

That someone finally arrives in Koichi Hirose and Rohan Kishibe, who can perceive the ghosts and, on learning the murderer still lives, agree to warn Morioh's Stand users. When Kira's own soul later lands in the alley and lunges at Reimi, Arnold clamps down and tears off his arm, making him turn back so that countless reaching hands can haul him into the afterlife. With the danger gone the alley fades, and Arnold ascends to Heaven at Reimi's side, both at last at peace.