Junichirou Tanizaki possesses a slim build, orange hair, hazel eyes, and pale skin. He typically wears an oversized off-white V-neck sweater, light blue pants, brown shoes, and a red sweater tied around his waist, with a light grey bobby pin clipped on the left side of his hair and matching earrings. For the Armed Detective Agency's celebration after the cannibalism incident, he wore a formal suit. When the Agency faced framing as terrorists, he adopted a white hood suit and later military police riot gear with black boots and gloves. Initially perceived as one of the Agency's most average members, Tanizaki lacks the eccentric traits of his colleagues but actively participates in missions under senior direction like Doppo Kunikida. He expresses insecurity about his combat usefulness due to his non-offensive ability yet demonstrates resilience in the Agency's dangerous work, adapting well to reconnaissance roles and leveraging his power for tactical advantage. Despite occasional nervousness in situations like visiting Ministry of Home Affairs bases or solo plane flights, he performs convincingly in undercover operations, such as posing as a bomber during Atsushi Nakajima's entrance exam, readily apologizing for harsh behavior afterward as role-play. Tanizaki's morality is highly situational, prioritizing self-preservation and the Agency's safety, even endorsing harming civilians or attempting lethal force against enemies. During existential threats to the Agency, he contemplated defecting to the Port Mafia. This impulsiveness risks collateral damage to Yokohama and colleagues, marking him as a liability despite his loyalty. His defining trait is his devotion to his younger sister, Naomi Tanizaki. Though embarrassed by her public displays of affection, he considers her safety paramount, declaring he would "burn the world" for her, reacting with violent fury to threats against her, such as threatening the Port Mafia's Black Lizard commanders with death. His ability, *Light Snow* (*Sasameyuki*), projects realistic illusions within a controlled area, often visualized as falling snow. Named after the real-life author's novel *The Makioka Sisters*, it manipulates perceptions by concealing objects, creating false scenery, or replaying events. This power aids in stealth, evasion, and combat coordination—masking allies during the Guild arc or disorienting foes like Lucy Maud Montgomery. He also possesses cooking skills, preparing dishes like Hayashi rice. Tanizaki lives with Naomi, having joined the Agency after leaving school. His entrance exam was notoriously traumatic, with memories he subconsciously buries. He engages in key conflicts: against the Guild on the Moby Dick airship, during the Cannibalism arc's alliance with the Port Mafia, and while evading the Hunting Dogs after the Agency's framing, coordinating with allies like Atsushi and Kenji Miyazawa and utilizing *Light Snow* for tactical advantages. His Agency relationships are multifaceted: he defers to Kunikida as a mentor, collaborates supportively with Atsushi during missions and stakeouts, fears Akiko Yosano due to her invasive medical treatments yet volunteers to join the Mafia in her place when her past endangers her, shares camaraderie with Kenji and Kyoka Izumi—whom he photographed affectionately during Fukuzawa's recovery party—trusts Ranpo Edogawa's strategic judgment unconditionally, and views Osamu Dazai as a capable but manipulative senior. Unresolved elements include theories about Naomi's nature. Some interpretations, based on themes from Tanizaki's namesake author, suggest she could be an illusion created by *Light Snow*, paralleling literary motifs of idealized women and unreliable narrators. Alternatively, their sibling relationship might conceal a romantic involvement, echoing the real Tanizaki's novel *Naomi*, where a couple poses as cousins. Foreshadowing also hints at a potential shift to the Port Mafia, reflecting the author's transition from Western fascination to traditional Japanese aesthetics.