Isshin Kakihara is a freelance journalist with black hair and grey eyes. He typically wears suits, draping the jacket casually over his shoulders, and is frequently seen smoking. His blood armament manifests as large, enhanced fists, aligning with his physical combat style. Thirteen years before the main events, his parents committed suicide, an event that profoundly shaped his outlook and fueled a deep-seated resentment toward Chihiro Kamina. Kakihara holds Chihiro responsible for his parents' deaths, though the truth involves Chihiro's father attempting to kill him before committing suicide. This misconception drives Kakihara's hostility and fixation on Chihiro, whom he investigates journalistically due to the incident. He exhibits a tendency to avoid personal accountability, redirecting blame onto Chihiro for tragedies, including the transformation of his associate Tsubasa into the monstrous entity Aero. Despite his abrasive and cynical exterior, Kakihara demonstrates loyalty and self-sacrifice. During a confrontation with the scythe-wielding antagonist Kaburagi Kark, he intervenes to protect Chihiro, deliberately taking a fatal blow intended for him. With his final act, he urges Chihiro to survive and live on behalf of the perished, acknowledging a buried sense of responsibility and completing an arc from resentment to reluctant guardianship.