Kaika Itsuki, a 30-year-old politician vying for mayor of Shiniki—an experimental autonomous zone testing progressive laws—champions the legalization of suicide as societal reform. Framing it as empowerment to "befriend death," he promotes self-sacrifice for collective gain, driven by personal stakes: his son’s congenital heart defect compelled Kaika to attempt donating his own heart via suicide, barred by laws prohibiting organ donations from suicides. His campaign merges pragmatic rescue efforts with a philosophical crusade to normalize death as a communal benefit.

Short grayish hair and formal suits underscore his political rigor. His name, blending "open" (開) and "conversion" (化), mirrors his radical reformist identity. Yet beneath his public zeal lies collusion with Ai Magase, a manipulative ally who coerces opponents into suicide, eroding his rhetoric of free choice and casting him as a secondary antagonist shrouded in moral compromise.

Torn between paternal duty and political ambition, Kaika’s initial altruism clashes with his reliance on Ai’s destabilizing tactics, blurring the line between saving his son and exploiting Shiniki’s chaos. His son’s symbolic parliamentary bid—a protest against the suicide law—fuels familial strife, leaving unresolved whether Kaika’s motives stem from selflessness or opportunism.

Embedded in debates over legal ethics and human rights, his policies challenge sanctity-of-life norms, yet unanswered questions about his ties to Ai and sparse backstory sustain ambiguity, emphasizing unresolved tension over closure.