TV-Series
Description
Masamune Kido commands Border, the organization defending Mikado City from interdimensional Neighbors. His appearance features short black hair slicked back from a slight widow's peak, slate gray eyes, and a lightly tanned complexion. A prominent scar runs down the left side of his face, with expert medical staff unable to restore his lost eyebrow. Kido typically wears formal suits reflecting his rank. In Border's early days, he had longer hair and no scar, indicating the injury occurred during the organization's formative tragedies before it went public.

Kido demonstrates a serious and strict personality, condemning rule violations sternly. He initially ordered Yūma Kuga's elimination for being both a perceived hostile Neighbor and dangerous Black Trigger wielder—despite Yūma being the son of Kido's former colleague Yūgo Kuga—yet prohibited lethal force during capture operations. Over time, he promised Yūma safety upon regulatory compliance and later permitted his Black Trigger use during the Second Large-Scale Invasion under restrictions.

His leadership philosophy prioritizes organizational strength and victory, epitomized by his belief that "strategy is meaningless if it doesn't lead to victory." He approves pragmatic decisions like enrolling the Neighbor Hyuse as a Border agent. Kido displays unexpected administrative empathy, calmly responding to cash incentive requests during Away Mission Tests and promising generous stipends. He maintains personal preferences for family, old movies, and black coffee.

Kido founded and leads Border’s largest faction, advocating hostility toward Neighbors and prioritizing away missions over defense. This stance propelled Border’s growth by aligning with Mikado City’s anti-Neighbor sentiment. Despite his faction’s ideology, Kido’s personal views appear more nuanced. He permitted Neighbors in Tamakoma Branch, including Michael Cronin and Aristeran refugees, suggesting his actions strategically serve organizational expansion. His faction’s size contrasts with the smaller Shinoda Faction focused on defense and Tamakoma Branch seeking Neighbor diplomacy.

As a surviving Border founder, Kido assumed leadership after over half the original members perished during a Neighborhood military support mission. He reformed the organization, with founders like Masafumi Shinoda and Ryoji Kiriyama joining his system. This history underpins his commitment to Border’s integrity. Director Rindō noted Kido’s hardline policies attracted recruits, while Yūichi Jin suspected Kido’s actions during the Black Trigger Capture Arc conflicted with his "true goal," prompting Kido to revoke threats against Yūma.

Kido’s relationships reveal complex leadership. He initially deemed Osamu Mikumo expendable for rule-breaking but later encouraged him to "Work hard to reach your goals." Following agent Hiura’s resignation, Kido expressed genuine well-wishing for young people’s futures. His interactions balance uncompromising authority with unexpected support for agents whose goals align with Border’s interests.