Décalcomanie Book 1: Reliving the Past

Yongsun and Wheein, twins who were deeply loved their parents, but their father unable to cope with their mother's passing, became a drunkard and began physically abusing them. Both Yongsun and Wheein wished for a better life yet they only had each other.

Everything changed once Wheein's undetected condition got worse and eventually led to her sudden passing as she tried to save Yongsun from their father's harmful actions.

Since then, Wheein's spirit watched over Yongsun although Yongsun herself was unaware & the both of them knew that they could no longer physically be with each other yet they were inseparable, not even death could keep them apart.

At first Yongsun was unable to see the ghost of her sister, but because of an accident, she was able to see her, despite falling unconscious afterwards.

Since then, Yongsun had Wheein by her side again, though people thought she had gone crazy for "talking to herself", which drove Wheein to backfire on the people who hurt her beloved sister.

Despite having misconceptions with her sister's actions, Yongsun became conscious of what people thought & lied whenever she faced other people, without putting Wheein in the picture, which angered her sister.

Many kids teased Yongsun as she & her aunt moved to a new village, but there was only one who befriended her, and that was Jin.

Taehyung was left behind in the old village, where he grew up under his aunt's care after his parents were arrested for false accusations. Years passed and Wheein & Yongsun, now both 17 years old, grew up relying on each other though some people were confused with Yongsun only "talking to air", especially Sowon, who became long time rivals with Yongsun since they were kids. This angered Wheein & she decided to haunt Sowon in exchange for how she has been treating her, which Yongsun did not approve of.

The twins then had conflict between them & this made Wheein so furious that never showed herself to her sister again, at least for now.