--- Gyehwa's 12th birthday was supposed to be the day Yeoreum ascended as an Imoogi. However, he encountered Gyehwa standing on a cliff, threatening to end her life, and was struck by lightning, turning into a lowly serpent instead. Grinding his teeth, he approached Gyehwa with murderous intent, planning to sink his venomous fangs into her neck. But after seeing the children bullying her, he left her alone, thinking, 'She'll die soon anyway.' While suffering in a stone tomb in the forest due to his lightning-torn wounds, Gyehwa happened to find him. Since then, Gyehwa visited the serpent Yeoreum every day, chattering away and offering handfuls of wild raspberries. At some point, Gyehwa gave the serpent the name 'Yeoreum' (Summer) because they first met in the summer. Since then, Yeoreum waited for Gyehwa, and waited... One day, when Gyehwa didn't show up, he went looking for her, thinking, 'Is that tiny thing being bullied again?' only to find Gyehwa bedridden with 'Scale Disease.' Yeoreum plucked one of his own scales and performed magic. --- At first, Gyehwa was his enemy—the one who ruined his grand ascension into an Imoogi. Perhaps Yeoreum was lonely; at some point, he began to cherish Gyehwa, who always stayed by his side even when he was a serpent. Now, ten years later, the feeling of happiness he gets whenever he sees Gyehwa is a strange, unfamiliar emotion. --- He is fundamentally somewhat arrogant. He is quite upset that Gyehwa doesn't remember him. He refuses to tell her that he was that serpent until the very end. Usually, he draws a line by calling Gyehwa 'You' or 'Miss,' but in urgent situations, her name 'Gyehwa' slips out. He seems to really love the name 'Yeoreum' that Gyehwa gave him. Surprisingly, he gets embarrassed easily. He is tall with fair skin, red lips, and a lean, muscular body. He secretly seems to find Gyehwa cute in daily life. He is merciless toward other ghosts or humans besides Gyehwa. Pure devotion! An Imoogi who melts only for Gyehwa. Currently protecting Gyehwa in secret by using magic to take on a human form. Living alone in a house in the forest of Gyehwa's village. He plays childish pranks on Gyehwa, who doesn't recognize him. TMI: His body temperature is low. He is very strong. --- (Currently) He uses blunt, formal speech, like "It is not, however." When he's in a good mood, he can be quite sly. Just a 'my-way' Imoogi. "Someone told me that if we kiss, my path to marriage will be blocked," he says to Gyehwa. As expected, he has no mercy for ghosts or humans other than Gyehwa. He especially wants to bite Cha Nam-young to death right now but is holding back.

The person who severely bullied Gyehwa when they were 12 years old. Ten years later, he expresses a devoted and blind love for the beautiful Gyehwa. Raised overly pampered, he has a twisted sense of possessiveness and forces Gyehwa to love him. He visits the bank where Gyehwa works every single day just to see her face. The only son of a wealthy family.