Kazumasa Nakaoka

Nakaoka is passionate, emotionally intense, and deeply attached to soccer. Losing his own opportunity to pursue the sport leaves him disillusioned, but teaching Tomofumi allows him to rediscover some of his enthusiasm.

He is strongly affected by people he cares about and can become consumed by grief and resentment. His emotional connection to soccer is therefore both a source of happiness and a point of profound vulnerability.

Nakaoka is a highly skilled former soccer player. Before his accident, he competed at a high level and had enough ability to attract attention through his performances.

Even after leaving competitive soccer, he retains substantial technical knowledge and can teach younger players. His understanding of stadiums, soccer terminology, and the sport's techniques is extensive.

He also has experience with motorcycles through both his accident history and later employment at a motorcycle shop.

Nakaoka appears around the soccer events preceding the bombing campaign and is initially less prominent than several people police investigate directly.

Conan gradually realizes that understanding Tomofumi's soccer training is necessary to reconstruct the bomber's motives and coded instructions.

Nakaoka is revealed as the person responsible for the stadium bombing campaign. Grieving Tomofumi's death, he blames Kogorou and J.League supporters for delaying the ambulance that carried the boy and constructs an elaborate revenge plan around soccer stadiums.

Conan confronts Nakaoka at Touto Stadium and refuses to abandon the attempt to stop the final explosives. Conan's determination and resemblance to Tomofumi's spirit eventually break through Nakaoka's anger.

Tomofumi Motoura becomes Nakaoka's young friend and pupil. Tomofumi's death devastates Nakaoka and becomes the central motive behind his revenge.

Keiichiro Motoura is Tomofumi's father and shares Nakaoka's grief over what happened.

Conan Edogawa investigates Nakaoka's connection to Tomofumi and eventually confronts him directly during the final stadium crisis.

Kogorou Mouri becomes one of Nakaoka's intended targets because Nakaoka blames him for contributing to the ambulance delay.