Masato Kaibara is a supporting character in the anime Ghost Hound, primarily connected to the protagonist Makoto Oogami as the husband of Makoto's mother. His background is marked by tragedy: he apparently died during an incident in which Makoto's mother attempted suicide, and his spirit continues to exist in the spirit world known as Kakuriyo, where he takes on the identity of Snark. Within that realm, he encounters Tarou Komori, one of the three main teenage protagonists, and his interactions there are significant to the unfolding of the story's supernatural events.

In terms of personality, Masato is portrayed as highly intelligent and comes from a privileged family, yet he feels deeply misunderstood and isolated from those around him. He is fiercely independent and dislikes relying on others, which often makes it difficult for him to form close connections. His traumatic childhood experiences have left him with recurring nightmares and a strong interest in the supernatural. He tends to approach problems with a logical and analytical mindset, focusing on long-term strategic planning rather than short-term goals. He is also assertive and confident, with a strong desire to maintain control and autonomy over his own life. This need for control can manifest as quick anger when his authority or power is challenged, and his intense emotional drive sometimes overrides his logical reasoning.

Masato's motivations are rooted in confronting the trauma of his past and understanding the supernatural occurrences that have shaped his life. He becomes involved in the investigation of a mysterious cult rumored to practice occult rituals in his hometown, and he works alongside his friends to uncover the secrets of both the cult and the paranormal events plaguing the region. His journey throughout the series is one of self-discovery, as he learns to trust others and cooperate with them, gradually coming to terms with his own fears and embracing his abilities to face the unknown.

Key relationships include his connection to Makoto, his stepson, whose own trauma is intertwined with Masato's death and the family tragedy. He also has a notable link to Tarou, as they meet in Kakuriyo under Masato's Snark persona, and this encounter provides crucial information about the spirit world and the broader mystery. His role in the story is to serve as a bridge between the living world and the unseen world, providing insight into the nature of Kakuriyo and the events that set the main plot in motion. His character development involves moving from a state of isolated independence toward a greater understanding of the importance of trust and cooperation, as he confronts his past and uses his abilities to navigate the supernatural realm. As a spirit, his notable ability is the capacity to wander through Kakuriyo, observing and interacting with the living characters who enter that realm, and his knowledge of the spirit world is vital to the protagonists' quest.