Zen Seizaki, a public prosecutor in the Tokyo District Public Prosecutors Office’s Special Investigation Department, navigates high-stakes cases with a fierce sense of justice and methodical precision. His career centers on unraveling systemic corruption, from pharmaceutical scandals involving falsified drug data to political machinations distorting the Shiniki district’s mayoral elections. These inquiries expose a sprawling conspiracy advocating the experimental legalization of suicide—a scheme engineered by shadowy figures seeking to reshape global societal norms.

Born under a name signifying “good” and a surname embodying moral steadfastness, his identity mirrors an unyielding ethical code. Initially entrenched in administrative prosecution, he shifts to international investigations after being recruited by Alexander W. Wood, broadening his scope as personal risks intensify. His pursuit of justice collides with Ai Magase, a cunning antagonist orchestrating mass suicides and psychological warfare, deepening both professional and personal stakes.

Married to Hitomi Seizaki and father to young Asuma, his family anchors his resolve amidst chaos. A bloodstained document discovered during the pharmaceutical case propels him into a web of political deceit, where he tragically witnesses the suicide of assistant Atsuhiko Fumio and the brutal murder of partner Hiasa Sekuro—kidnapped and dismembered by Magase. These losses fuel his obsession to dismantle her influence.

Resigning from the prosecutor’s office after recognizing Magase’s transnational reach, he abandons his career and homeland, refusing to compromise with a corrupt system. His journey epitomizes a relentless clash between morality and apathy, marked by eroded trust in institutions, philosophical turmoil, and sacrifices that redefine his understanding of justice.