Himori Akiyama is a clansman of Scepter 4, an organization that operates under the Blue King. He holds the rank of commander within the Special Duty Corps, a unit formed to handle beta class emergencies involving Strains. His physical appearance includes a slim build, green hair that reaches his neck and covers his right eye, and black eyes. He wears the standard Scepter 4 uniform, a blue overcoat with black and gold lining over a white shirt, dark blue pants, and knee-high black boots. His personality is serious and professional, a demeanor stemming from his military background. He maintains a calm attitude at work and often reminds his fellow clansmen to act with the same composure. He is honest and modest but has a tendency to panic when situations become uncontrollable. He rarely engages in activities outside of his duties within Scepter 4. Akiyama was recruited into Scepter 4 alongside Yūjirō Benzai by Reisi Munakata due to their military experience. He rose to become commander of the First Squadron of the Swordmen Division before the formation of the Special Duty Corps. In one documented incident, he pursued an escaped horse Strain with Andy Dōmyōji. They encountered four clansmen from HOMRA during this mission. Akiyama consistently reminded Dōmyōji to remain calm as tensions flared with the Red Clansmen. The situation resulted in the Strain being scared away while Anna Kushina was riding it. Within the series plot, Akiyama participates in several operations. He was present during a confrontation with HOMRA at a hotel suite, drawing his sword under orders but standing down when the situation was resolved peacefully. He extracted and analyzed the video of Tatara Totsuka's murder, reporting his findings to Saruhiko Fushimi. He accompanied senior officers to Ashinaka High School for an investigation and was later part of a team that attempted to apprehend Yashiro Isana on a freeway and at a soccer stadium, where he was caught in an illusion dispelled by Munakata. He also participated in the failed mission to retrieve the Silver King from the Himmelreich, which crash-landed. Following Mikoto Suoh's jailbreak from Scepter 4 headquarters, Akiyama was among the clansmen who attempted to prevent his escape but was ordered to stand down. He later engaged in combat against HOMRA members at Ashinaka High School, where he fought Shōhei Akagi, and witnessed the emergence of a beam of silver light from the school. As a member of the Blue Clan, Akiyama wields a Blue Aura. His primary weapon is a saber named Taruhi, which is standard issue for Scepter 4 members. Regarding the specific production "K: Seven Stories - The Idol K," a spin-off depicting characters as idols and producers in the entertainment industry, the provided search results contain no concrete or direct information pertaining to Himori Akiyama's role or appearance.