Akina Hiizumi, an 18-year-old human male, directs the Hiizumi Life Counseling Office under Sakurashin's employ. His signature power, "tuning," stems solely from his bloodline and forcibly severs youkai connections to the human world, banishing them to their native dimension. This ability triggers a visible lengthening of his hair during activation. As the current oyakume—a hereditary role preserving balance between realms—he must eventually be tuned by his successor, just as he tuned his own grandfather before him.

His casual, approachable style diverges sharply from predecessors' strict methods, fueling skepticism about his efficacy among townspeople and youkai alike. Some youkai equate tuning to murder, deepening their distrust. Kyosuke Kishi recurrently criticizes Akina’s leadership, occasionally piercing his usual resilience to provoke hesitation or self-doubt. Akina shares frequent meals with Hime Yarizakura at Hou Hou Ran, a local Chinese restaurant, underscoring their closeness.

Tasked with protecting Sakurashin, Akina collaborates with counseling office members Hime Yarizakura, Ao Nanami, and Kotoha Isone to neutralize threats to the town’s harmony, including disruptive youkai and external foes like youkai hunters. His connection to Sakurashin’s past intensifies through clashes with Enjin Hiizumi, a centuries-old relative previously tuned by Akina’s ancestors. Resurrected in Gin Nanami’s body, Enjin seeks vengeance by merging both worlds via "Striking"—a power to summon youkai-world entities. He exposes disturbing truths about tuning’s consequences and wields a limited version of the ability himself, heightening Akina’s physical and psychological struggles.

Amid overarching conflicts during Tsuki ni Naku, Akina maintains routines like onsen visits with colleagues, reflecting daily life’s persistence. His duty remains upholding the town’s coexistence principles while bearing the moral gravity of his legacy and the inevitability of his own future tuning.