Ryuu Achiya

Achiya receives little direct characterization because his role is reconstructed primarily through the serial murder investigation.

The film focuses on his connection to the other targeted people rather than developing a separate personal storyline.

No supernatural abilities, specialized fighting skills, or distinctive investigative talents are established for Achiya.

His narrative significance comes from his involvement in the past event that connects the murder victims.

Achiya is among the individuals whose cases become part of the joint police investigation in The Raven Chaser. Mahjong tiles left in association with the killings indicate that the murderer is following a deliberate pattern.

The victims are eventually connected through a hotel fire in which Nanako Honjo died. Their presence during that incident provides the apparent reason they are being targeted.

The investigation surrounding Achiya and the others eventually overlaps with the Black Organization's attempt to retrieve sensitive information from the case.

Nanako Honjo is connected to Achiya through the hotel fire that becomes the common link between the murder victims.

Kosuke Mizutani believes those connected to the fire bear responsibility for Nanako's death and becomes central to the apparent revenge motive.

Conan Edogawa investigates the pattern linking Achiya to the other people in the case.