A reel braking adjustment device includes a tensile force-related information acquisition unit and a braking parameter correction unit. The tensile force-related information acquisition unit is configured to acquire tensile force-related information. The tensile force-related information is information that is related to tensile force acting on a fishing line and detected during a fishing line discharge period in which the fishing line is released from a dual-bearing reel configured to brake rotation of a spool based on a braking parameter. The braking parameter correction unit is configured to correct braking parameters based on temporal changes in the tensile force-related information acquired by the tensile force-related information acquisition unit.
