Reiji Kiriya

Kiriya is cruel, vindictive and obsessed with settling grudges. Humiliation does not fade with time for him; instead, he plans retaliation and recruits others to help carry it out.

He is also manipulative. Rather than simply confronting Oga alone, Kiriya uses his influence over Teimo Tech's delinquents to create a larger crisis around Saint Ishiyama.

His confidence depends heavily on controlling the circumstances. When confronted with strength far beyond what he anticipated, that composure deteriorates rapidly.

Kiriya is an experienced delinquent fighter, but his primary threat comes from organization and numbers rather than extraordinary individual strength.

He commands Teimo Tech fighters and receives support from its elite Shadow Force, allowing him to escalate a personal grudge into a large confrontation.

His three facial scars were inflicted using his own fingernails, leaving a permanent reminder of his earlier encounter with Oga.

Kiriya is central to the history connecting Oga and Miki. During middle school, his gang targets Miki and provokes an encounter with Oga that later contributes to Miki's resentment.

He returns after the students transfer to Saint Ishiyama and organizes Teimo Tech delinquents to take revenge.

The resulting confrontation forces Oga and Miki to face both their unresolved misunderstanding and Kiriya's Shadow Force. Oga ultimately overwhelms Kiriya with the Zebub Blast, terrifying him with the scale of the power he has challenged.

Tatsumi Oga is the main target of Kiriya's revenge after their violent middle-school encounter.

Hisaya Miki is also central to that incident and becomes one of Kiriya's opponents when the conflict resurfaces.

Koutarou Mikagami, Unshou Onizuka, Kousei Kuroki and Takumi Dezaki form the Shadow Force supporting Kiriya during his attack.