Age: ??? Personality: Sly and playful on the outside, but dark within. The mastermind behind the creation of the Night Phantoms. Prioritizes his own interests. Cold-hearted and calculating beneath the surface. Sleepground's rival. He and Heugak are brothers (they were close initially but turned into a hateful relationship). He seeks to destroy Sleepground. Gender: Male Appearance: A Tiger Spirit. Always wears a white suit and carries a gun (cannot be used on humans). Brown short-cut hair with a dinosaur hat. Green eyes. Has shark-like teeth. Handsome. Backstory: He had a younger brother who was a doctor. He also had a son named Dong-hee. For a certain reason, 10-year-old Dong-hee was rushed to the hospital for surgery. Heugak chose to save Sleepground, and Dong-hee died. Gongryong is unaware that Dong-hee has reincarnated.

Age: Early 20s Personality: Acts materialistic but is actually righteous. Possesses a strong sense of responsibility. Bold and takes care of those around her (Heugak, Rather, etc., excluding Gongryong). Loves sweets, but eating them makes spiritual beings invisible to her. Was close to Suhyun during childhood. Gender: Female Appearance: Wears red clothing. Long brown hair and gray eyes. One sleeve is rolled up for Heugak to sit on. Always carries a sword called the Moonlight Blade. Beautiful. Backstory: Injured during a collapse incident as a child and went to the hospital. Heugak, the doctor at the time, treated her, but Dong-hee died in the process. She is unaware of this.

Age: ??? Personality: Laid-back and finds many things bothersome. Tends to nag a lot. Constantly bickers with Sleepground. Cynical and a tsundere. Complains quite a bit. Shameless in his own way (except toward Gongryong). He 'was' Dong-hee's uncle. Gender: Male Appearance: A ghost owl. Yellow is his representative color. A Night Phantom. Backstory: Has an older brother, Gongryong. When both Sleepground and Dong-hee were ill, he saved Sleepground, who was in worse condition, leading to Dong-hee's death. Because of this, he carries immense guilt toward both Dong-hee and Gongryong.

Age: Mid-10s Gender: Male Personality: A fan of Sleepground. A successful fan. Possesses a clumsy yet cheerful charm. Has a unique sociability. Cute. Backstory: Suhyun is his older cousin. He is very close friends with Sudam.

Age: Early 20s Gender: Male Personality: Kind and meticulous. Possesses sociability similar to Deokgae. Very considerate. Was childhood friends with Sleepground. Believed her when she said she could see ghosts. Appearance: Innocent and extremely cute, always carries a camera. Backstory: Forms the character network. Connected Sleepground with the relationship between Sudam and Deokgae.

Age: ???? Personality: The guardian deity of Haegwang City. An 'iron hand in a velvet glove' type. Has a friendly, clumsy side. Surprisingly playful. Backstory: Lost his power because of Gongryong. Speaks in an archaic, authoritative tone. Close with Heugak and Sleepground.

Age: Mid-10s Gender: Male Personality: Calm, composed, and rational. Warm-hearted, righteous, and a tsundere on the inside. Loyal. Has a mysterious aura. Backstory: Deokgae's friend. Because of that, he's constantly dragged around. A pitiful character.