Siblings Hari and Doori live in the haunted Shinbi Apartments. One day, they meet and befriend the goblin who feeds off the magical energy there, Shinbi. Despite his warnings, they steal and eat the goblin taffy, granting them the ability to see ghosts. They agree to help Shinbi drive away ghosts from the apartment, so that it stays occupied and he can continue feeding off the energy generated. Shinbi gives them each a Ghost Ball, allowing them to summon spirits they've defeated to help them.
Using their Ghost Balls, Hari and Doori protect their neighbors and classmates from evil spirits and help ghosts cross over to the other side.
This show provides examples of:
- Adult Fear:
- many of the ghosts have backstories involving car crashes, children wandering off and drowning, losing your family, and other sobering, real world tragedies in contrast to the colorful cast and otherwise playful tone of the series.
- The Koo's father's chronic unemployment and constantly failing job interviews is something any father would fear.
- All Girls Want Bad Boys: Kanglim has quite a following despite being cold and indifferent with no regard for the feelings of the girls who confess to him. Even Hari finds herself attracted to him in spite of disliking him for his personality, and she and her friends acknowledge that he only gets away with treating people as he does because he's attractive.
- Berserk Button: do not call Shinbi a dwarf.
- Big Eater: Shinbi and Doori.
- Calling Your Attacks: nearly every instance of Shinbi using magic, as well as many of Kanglim's attacks.
- Friendly Neighborhood Vampire: Ian
- Jerk with a Heart of Gold: Kanglim is aloof and indifferent to other's emotions, but he doesn't hesitate to help when he sees someone in trouble.
- Luminescent Blush: Hari gets this way around Kanglim.
- Our Goblins Are Different: Shinbi
- Red Oni, Blue Oni: Compassionate, high-energy Hari is the red oni to Kanglim's cold, reserved blue oni.
- Romantic Vampire Boy: Ian
- Sugar-and-Ice Personality:
- Gauen is outwardly cool and reserved, but sweet and loyal once you get to know her.
- Kanglim turns out to be one as well. Though still somewhat guarded even around Hari, it's shown that he does actually care, but is under too much stress to open up.
- Vile Villain, Saccharine Show: the Big Bad of the series is Underground Nation, the king of all darkness... Yep, Satan basically, the big bad to end all big bads.
- Vitriolic Best Friends: Shinbi, Hari, Doori, and Hyunwoo are this. They're always teasing each and Shinbi frequently steals Hari and Doori's food and otherwise annoys them, but they're always there for each other.
Episodes of this series provide examples of:
- Added Alliterative Appeal: nearly every episode is titled this way.
- Death of a Child:
- The Drowned Twins
- The No-Face Ghost's backstory
- Pet the Dog: episode 15 for Kanglim.
- Not So Stoic: Kanglim breaks down in episode 24, showing more emotion than he did in all previous episodes combined.
- Sleep Cute: Shinbi and Doori cuddling in episode 24. Aww.
- Weight Woe: Doori becomes insecure about being overweight in episode 3.