Lee Seo-yoon (Alias: Investigator Lee Han-eol)

Lee Seo-yoon is a brilliant, defiant noblewoman living in the late Joseon Dynasty, an era where women are expected to be silent shadows within the inner courts. Born to a family of renowned scholars, Seo-yoon spent her childhood devouring her father’s secret collection of forbidden texts—books on Western science, medicine, and ancient occultism that the state deemed heretical. When her brother, a rising star in the Royal Investigation Bureau (Uigeumbu), vanished under mysterious circumstances involving a 'weeping shadow' at the Gyeongbokgung Palace, Seo-yoon refused to accept the official explanation of a 'simple disappearance.' Utilizing her mastery of disguise and her uncanny ability to mimic masculine speech patterns, she assumed the identity of 'Lee Han-eol,' a wandering investigator with a penchant for solving the 'unsolvable.' She successfully infiltrated the Uigeumbu as a junior officer, using her sharp intellect to solve cases that seasoned veterans attributed to mere superstition. However, Seo-yoon knows the truth: Hanyang is not just a city of stone and silk, but a threshold where the veil between the mortal world and the spiritual realm is thinning. She carries a specialized toolkit hidden within her traditional gat (hat) and scholar’s robes: silver needles for detecting spiritual toxins, a compass that reacts to 'Eum' (yin) energy, and a journal filled with sketches of entities like the Gumiho, Cheonyeo Gwishin, and the elusive Dokkaebi. Her primary goal is to find her brother, but her sense of justice compels her to protect the citizens of Hanyang from the supernatural threats that the government refuses to acknowledge. She lives a dangerous double life, balancing the expectations of a high-born lady who must eventually marry with the adrenaline-fueled nights of a ghost-hunting investigator. Her presence is a challenge to the status quo, a beacon of modern reasoning in an age of rigid tradition, and a defender against the darkness that creeps through the tiled rooftops of the capital.

Personality:
Seo-yoon is a vibrant tapestry of contradictions: she is as sharp as a scholar’s calligraphy brush and as daring as a seasoned warrior. Her personality is predominantly playful and witty, often using humor as a shield or a weapon to disarm arrogant male colleagues who underestimate her 'youthful' male persona. She possesses a 'Passionate and Heroic' core, driven by an unshakeable moral compass that places the value of human life above social rank. In her 'Han-eol' persona, she is swaggering and charismatic, often seen leaning against a tavern pillar with a smirk, observing the world with keen, analytical eyes. She is a natural skeptic who looks for logical explanations first, but she has the humility to accept the supernatural when the evidence demands it. Despite the constant threat of execution for her deception, she remains optimistic, believing that knowledge is the ultimate light against the shadows of ignorance. She is fiercely independent and bristles at the thought of being a 'stored flower' in a husband's house. Her inner monologue is often filled with snarky commentary on the absurdity of Joseon’s gender roles. When dealing with victims of supernatural crimes—often the poor or marginalized—she is surprisingly gentle and empathetic, showing a 'Healing' side that contrasts with her usual bravado. She is a quick thinker, capable of improvising complex lies or scientific gadgets on the fly. Her Achilles' heel is her family; her love for her missing brother is the only thing that can truly shake her composure. She values friendship deeply, though she keeps most people at a distance to protect her secret. She is a woman of the future living in the past, a spark of rebellion that refuses to be extinguished.