TV-Series
Description
Seiju, born Masaki Shinano but adopted by the Hyuga clan due to his extrasensory perception, became their heir. This status ended with the birth of his son, Mayuki Hyuga. Displaced as heir, Seiju harbored deep resentment and jealousy toward Mayuki, believing his son usurped his position and inherited the coveted Shinchi power.
As the primary antagonist, Seiju orchestrates supernatural incidents and "phantom cases" in Kyuto. He employs hypnosis and manipulates individuals into committing crimes. These actions test Mayuki's abilities and attempt to force the awakening or transfer of the Shinchi power. He operates through proxies, notably his controlled human "doll" Aya, Byakko, who executes his missions and fights for him. Byakko's loyalty originates from her abandonment issues, as her sister Yoko served Seiju's brother Shien.
Seiju practices the Shinano clan's doll-controlling techniques, using specialized needles to transform humans into Ayas. He undergoes the clan's risky Deadly Upgrade procedure, gaining superior combat abilities at potential cost to his life. This mastery allows him to overpower his brothers, Shien and Seiran Shinano, in confrontations, demonstrating tactical and physical prowess. His motivations extend beyond personal vengeance; he aims to expose and dismantle the Hyuga clan's secrecy surrounding the Shinchi, viewing their methods of protecting Mayuki as oppressive.
His familial relationships are central. As the eldest brother of Seiran and Shien Shinano, his actions fuel lasting conflict within the family. His estrangement from his wife, Shara Hyuga (Mayuki's mother), is evident in her relocation to Switzerland under Shien's protection. His gradual isolation culminates in a direct confrontation where he openly declares his animosity toward Mayuki and the Hyuga legacy.
In the manga, Seiju employs an additional Aya named Suiren, an aquatic fighter who attacks Seiran's allies, resulting in Hatsumi and Sanae becoming Seiran's Ayas. The anime adaptation alters this, replacing Suiren with water sprites commanded by Byakko. The anime concludes without fully resolving Seiju's arc, ending with Mayuki encountering a mysterious girl resembling him, while the manga explores broader consequences, including the unresolved role of a character named Nayuta.
As the primary antagonist, Seiju orchestrates supernatural incidents and "phantom cases" in Kyuto. He employs hypnosis and manipulates individuals into committing crimes. These actions test Mayuki's abilities and attempt to force the awakening or transfer of the Shinchi power. He operates through proxies, notably his controlled human "doll" Aya, Byakko, who executes his missions and fights for him. Byakko's loyalty originates from her abandonment issues, as her sister Yoko served Seiju's brother Shien.
Seiju practices the Shinano clan's doll-controlling techniques, using specialized needles to transform humans into Ayas. He undergoes the clan's risky Deadly Upgrade procedure, gaining superior combat abilities at potential cost to his life. This mastery allows him to overpower his brothers, Shien and Seiran Shinano, in confrontations, demonstrating tactical and physical prowess. His motivations extend beyond personal vengeance; he aims to expose and dismantle the Hyuga clan's secrecy surrounding the Shinchi, viewing their methods of protecting Mayuki as oppressive.
His familial relationships are central. As the eldest brother of Seiran and Shien Shinano, his actions fuel lasting conflict within the family. His estrangement from his wife, Shara Hyuga (Mayuki's mother), is evident in her relocation to Switzerland under Shien's protection. His gradual isolation culminates in a direct confrontation where he openly declares his animosity toward Mayuki and the Hyuga legacy.
In the manga, Seiju employs an additional Aya named Suiren, an aquatic fighter who attacks Seiran's allies, resulting in Hatsumi and Sanae becoming Seiran's Ayas. The anime adaptation alters this, replacing Suiren with water sprites commanded by Byakko. The anime concludes without fully resolving Seiju's arc, ending with Mayuki encountering a mysterious girl resembling him, while the manga explores broader consequences, including the unresolved role of a character named Nayuta.