Shadow Detective is the main antagonist of 2007 animated film titled Yobi, the Five Tailed Fox. A mysterious and strange figure, Shadow man often appears in Yobi's time of need, saving her life or otherwise assisting her on several occasions. Claiming to be curious about Nine tailed Foxes, the race of which Yobi is apart, he claims himself to be a detective and expresses his desire to help her obtain a human soul so she can become human, handing her a device which will harvest the soul by using the spell Roono-mi amas bin.
Yobi the Five Tailed Fox
Shadow Detective first appears when he save Yobi, whom disguise as a girl, from the Fox Hunter’s talisman’s influence in mountain school. He had Yobi followed him to a building, where she nearly fell to her death as she walks on collapsing staircase, and unintentionally enters a wedding party. Embarassed, she immediately get out, and caught herself at the alley (the staircase and wedding party presumably illusions that Shadow Detective cast to rid anyone who followed her albeit also affected Yobi as well). There, he introduce himself before Yobi, and sense her ambition to live among humans. Intrigued with her true nature, he offer her a mechanical soul-taker device, which allow her to took human’s soul so she could became wholly human. Albeit hestitant, she accept the offer, and Shadow Detective brough her back to mountain school.
Unbeknowist to Yobi, the device was mechanized heart of the Shadow Detective’s. When the bus that Yobi onboard crashed during the trip, she lost it by accident when save everyone, but unaware that the mechanical heart moved by it’s own under Shadow detective’s control. The mechanical heart later appeared when it tries to took away Geum-ee‘s soul when Geum-ee confess his love to her as his best friend. But due the interference of the fox hunter, Geum-ee’s soul return and Geum-ee tries to save Yobi. A chase ensues, and Geum-ee tripped into gateway to Canava, causes his death. Yobi was captured by fox hunter’s hounds but saved by a bear whom she met earlier, allow her to enter Canava to save Geum-ee.
There, Shadow Detective meet her again, and guide her to find Geum-ee’s soul, which manifests as pigeon with shining blue feathers. Just as Yoobi free Geum-ee’s soul, Shadow Detective uses his mechanical heart to took Geum-ee’s soul away, reveals true nature of both his and his mechanical heart. He then became solid again, and possessed whole room and emerged as a golem, with Yobi trapped inside.
With his golem body, he mocks Yobi, revealed that Canavan Guardian Spirits has took away his soul(a curse presumably for his unforgivable crime against the living when still human) and left him to live as shadow. That experience made him became bitter and obsessed to steal other human’s soul, no matter what it takes. Canava spirits attack him, and Shadow Detective fought them. However, his greatest mistake was left Yobi trapped in his body, whom freed absorbed Geum-ee’s soul, allow the Canava Guardian Spirit to recapture him and took him away, presumably to kill him once and for all.
However, Canavan spirits warn her that souls that enters Canava cannot leave unless she could use other soul to replace it. So, when Canavan spirits creates a cage for Geum-ee’s soul, Yobi took it away and uses her soul to replace Geum-ee’s. Canavan spirits was shocked at her choice, but she did it anyway, results in her death.
To honor her, Canavan spirit later freed her soul, allow her to reincarnated as true human at the end of the movie.