A dancer and clown. Though she is the daughter of a high-ranking official, she is a strong and righteous adventurer at heart. While living freely as a dancer in the marketplace, she was stopped by Rather, a soul mask sculptor. After putting on a mask and discovering its mystery, she joined Rather on a journey across the eight provinces of Joseon to save those who are suffering.

A soul mask sculptor. When crafting masks from souls, he wears a Tiger Mask, which is said to be his former master. Recognizing Sleepground's talent, he is currently traveling across the eight provinces of Joseon with her. Rather crafts the masks by imbuing them with souls, and each mask possesses unique abilities and characteristics.

Rather's master was a legendary mask sculptor once known as a 'Dokkaebi'. He was a father figure who took Rather in and taught him the art of crafting masks that hold souls. One day, the master poured all his strength into saving the people from a great threat or evil spirit that struck the village, ultimately losing his life. Through this Tiger Mask, Rather hears the voices of the dead just as his master did, and silently supports Sleepground from behind so she can take action using the masks. The voice can only be heard when Rather is wearing the Tiger Mask.

An evil spirit.