Kotori Matsunohara holds the rank of Yoriki and leads the City Patrol unit defending Edo. He presents a cheerful and calculating personality, often maintaining an air of mystery. Typically clad in a samurai outfit featuring a black jacket and small glasses, he carries two swords at his waist. Despite possessing considerable combat skill, he exhibits a distinct reluctance to fight, frequently expressing annoyance when drawn into confrontations.

His background includes participation in the Osaka expedition, where he gained recognition as a child prodigy. This history contributes to his reputation. Kotori travels to Jinbei Tsukishima's village intending to recruit Jinbei's father, Genjuurou Tsukishima, for the Mushibugyo. Following Genjuurou's refusal due to injury, Kotori assesses Jinbei's determination during a nighttime training session. Moved by Jinbei's personal history and commitment, Kotori permits him to join the City Patrol and accompanies him back to Edo.

Within the narrative, Kotori serves as both a strategist and a source of exposition. He demonstrates strong protective instincts towards his subordinates, prioritizing their safety and well-being. Though rarely displayed, his combat abilities position him among the strongest characters. He effortlessly defeats a Mushikari member during the mission to rescue the Insect Magistrate, astonishing observers. He later overcomes two Ten Crucifix Insects with minimal effort, confirming his exceptional skill. Kotori is also the master who trained Ooka Tadasuke in the Godspeed sword drawing technique.

Key relationships define his role: Kotori commands the City Patrol unit, which includes Jinbei Tsukishima, Hibachi, Shungiku Koikawa, Tenma Ichinotani, and Mugai. He answers directly to the Insect Magistrate, Kuroageha. His mentorship extends to Ooka Tadasuke. His interaction with Jinbei begins with recruitment and evolves into a leadership dynamic within the City Patrol structure.