Sagyou is a recent recruit to the Kanagawa Police branch's Vampire Countermeasure Division. He has short, celery-green hair, black eyes, and wears the standard division uniform: white shirt, green tie, black slacks, and matching shoes.

Initially holding significant respect for his senior officer Handa Tō, Sagyou's regard plummeted after witnessing Handa's true nature. Despite this, Handa frequently draws him into schemes. Sagyou considers himself the team's most rational member but acknowledges his growing susceptibility to the eccentric influences around him, especially Handa's, causing him personal frustration.

His personality includes distinct traits. Exposure to Ydan Ojisan's Y-beam revealed his attraction to mature women with "ripe breasts." Outside work, he intensely enjoys popping bubble wrap and is emotionally moved when presented with large rolls of it. He dislikes bubble wrap being discarded without his knowledge and scorns toys designed for endless popping.

Professionally, Sagyou is an exceptionally skilled sniper. Handa notes Sagyou has never missed a target, regardless of distance or movement speed, though Sagyou himself remains unaware of this marksmanship talent.

During a mandated infiltration operation at Ronaldo's residence ordered by Handa, Sagyou rescued a vampirized burdock root. He adopted it, naming it "Burdy," and formed a genuine bond with the creature.

Sagyou shares the same height as his sister. His documented involvement consistently shows participation in division operations, interactions reflecting his complicated dynamic with Handa, and an ongoing struggle to maintain professionalism within the Vampire Countermeasure Division's chaotic environment.