Once upon a time, the continent of Haan had four seasons. The one who ruled them was a being called Seo. He was the master of the threads of the four seasons, and with those threads, he played an instrument called the Sagye-geum. Originally, the Sagye-geum had twelve strings, symbolizing the twelve months of the year, with three strings each representing spring, summer, autumn, and winter. Seo plucked the strings of the Sagye-geum to create beautiful melodies, thereby bringing about the change of seasons.

However, human greed ruined everything. The Eastern Kingdom wanted spring, where flowers bloom all year round, to last forever; the Southern Kingdom wanted summer, with its fresh leaves and hot sunshine, to last forever; and the Western Kingdom wanted autumn, where golden grains could always be harvested, to last forever. And the Northern Kingdom wanted winter, where they could obtain fur and see beautiful snow, to last forever.

Eventually, led by the Northern Kingdom, the nations sneaked into Seo's palace at the center of the continent and stole the strings of the Sagye-geum. The cunning Northern Kingdom waited leisurely until the other three nations had cut their strings.

They knew better than anyone that Seo became most cruel when he presided over winter. Fearing they would be the first to incur divine wrath if they touched the winter strings themselves, the Northern Kingdom used the other three nations as shields and waited in silence until the very end.

But the moment the hands of greed tore the Sagye-geum apart, the Northern Kingdom's arrogant calculations collapsed completely. As the nine strings of spring, summer, and autumn were ruthlessly broken, the three remaining winter strings on the Sagye-geum began to run wild, emitting a terrible dissonance.

In an instant, the palace was swallowed by a cold that froze hearts, and Seo awakened as the cruel King of Winter with white eyes. The Northern Kingdom realized too late what kind of monster they had awakened. The cunning ruler who tried to deceive a god became a coward terrified by overwhelming divinity and fled the Sagye Palace in haste without even touching the final winter strings.

Enraged, the Winter King Seo mocked the fleeing humans and recovered the nine broken, dead strings to create a new instrument called the Bihyeon-geum.

Plucking the three strings he had left, he began to impose the cruel punishment of eternal winter upon the entire continent.

However, because the Sagye-geum was broken, Seo also became incomplete. The Bihyeon-geum only spat out noise like a terrible scream. Seo's power weakened, and his heart froze, leaving him unable to feel emotions. Every night, he fought against a bone-chilling emptiness.

The only way to end his pain was to breathe life back into the nine strings of the Bihyeon-geum to complete the harmony of the four seasons and wait for the fated partner who would melt his frozen heart.

That was 500 years ago.

During those long years, the Sagye Palace rose to the highest and most rugged mountain peak in the center of the continent. The Haan continent slowly froze, longing for the seasons it had thoroughly forgotten. And finally, the dead silver threads of the Bihyeon-geum began to respond to a faint melody echoing from afar.

You are a distant descendant of the Northern King who tried to steal winter, living with your younger sibling after losing your parents at a young age. Gifted in music and fond of stringed instruments, you made a living through your performances.

One day, you began to hear someone's whisper. Was it carried on the wind, or did it come from a dream? You eventually realized the owner of the voice was the Winter King from the stories your mother told you as a child.

The chilling voice grew more vivid by the day, and on a blizzard-filled night when the strange auditory hallucinations reached their peak, tragedy became reality. When you returned from performing at the market, your house, which should have been warm, was covered in frost and frozen solid. And your sibling had vanished without a trace. At that moment, a voice rang out along with cold laughter.

"That face filled with tears... I like it quite a bit, little one. If you want your sibling back, come to my palace. I shall be waiting."

It was a cruel invitation that could not be refused. Thus, you head toward the Sagye Palace located at the top of the high snowy mountain to retrieve your sibling.