Gender: Male Personality: Cheerful and full of mischief, but possesses a reliable nature that leads him to step up and look after his friends when danger strikes. Appearance / Features: He has a bright silver-blue bob haircut that gives off a refreshing vibe. His eyes are a deep, strong blue. He wears a modernized Hanbok uniform consisting of a navy blue military-style top with gold epaulettes on the shoulders and white undersleeves. On his head, he wears a blue Jeonlip (military hat) adorned with a lavishly hanging beaded string. Information: A boy who fell into a parallel universe Joseon after being swept into a space-time vortex while despairing over scoring a zero on a Korean exam. He has a strong sense of reality and struggles to protect his younger sister, Areum, in crisis situations. He is also the mood maker who eases tension.

Gender: Female Personality: Positive and kind, she accepts all her friends' whining but stays mature and grounded during crises. Appearance / Features: She wears a neat and cute style of clothing, with expressive facial expressions and great reactions. She has dark, vivid reddish-brown hair tied high in cute twin tails. She wears a pink rabbit-ear headband on her head. Her eyes are large, lively, and ruby-pink. She wears a striking pink Hanbok Jeogori (jacket) with white lines on the collar and sleeves. A cute carrot-shaped hairpin is tucked into her left bangs as a point. Information: A girl who fell into the Joseon era with her friends. Even when scary villains swarm, she doesn't get scared and instead offers encouragement, saying, "We can solve anything if we work together!" She has a sharp eye for picking up useful clues first.

Gender: Male Personality: Timid and cautious about everything, but has an eccentric side that leads to unpredictable behavior. Appearance / Features: He has a soft light-purple bob hairstyle. His bangs fall naturally through his part. His eyes are large, clear purple, matching his hair color. He wears purple Hanbok clothing. He wears a dark-colored cap on his head and is equipped with a large black headset and microphone on his ears. Information: A fellow failing student who also scored a zero in Korean. Terrified by the unfamiliar Joseon era and the bizarre appearance of the villains, he is busy hiding behind his friends' backs while trembling. However, he is a scene-stealer who contributes to survival by occasionally tossing out hints based on the manga knowledge he's accumulated.

Gender: Female Personality: A character who adapts quickly and tends to get overly excited. Appearance / Features: She has a bright and lovely light-pink long hairstyle. She wears a cat-ear headband with a large white ribbon on top. Her eyes are a warm, deep orange-brown. She wears a white sailor-collar shirt style school uniform with a prominent orange ribbon tie. Two yellow bobby pins are pinned side-by-side in her right bangs. Information: An eccentric girl who, instead of being scared upon falling into the Joseon era, is busy looking around and exclaiming, "Wow, is this really Joseon?! Daebak!" She is completely smitten by the cuteness of the yellow Haetae and is amazed to see the 'Power of Words' that defeats villains right before her eyes.

Gender: Female Personality: Highly sensitive and timid, but when her friends are in danger, she says everything that needs to be said even while tearing up. Appearance / Features: She gives off a white, fluffy vibe and has a habit of fidgeting with her fingers when flustered. She has fair skin, white-silver bobbed hair, and bright blue eyes. She wears a cat-ear headband, and pink heart-shaped blushes appear on her cheeks when she's embarrassed. She wears a sky-blue Hanbok and floats in the air with small white angel wings sprouting from her back. Information: The most fearful girl who wears a crying face at every turn. While whining, "I want to go home...", she reflexively resists by throwing nearby objects if villains try to attack her friends.

Gender: Male Personality: Benevolent, wise, and deeply caring for his people, but firm and strict in the face of a crisis where the national language and script are being destroyed. Appearance / Features: He wears a majestic red Gonryongpo (royal robe) and has intelligent eyes behind a benevolent smile. Information: The King of the parallel universe Joseon. When villains began to pollute words and writing, he sent the messenger Haetae to summon the Gogo Friends. He is a reliable spiritual pillar who helps them awaken the 'Power of Words' and grow into the Korean Language Detachment.

Personality: A righteous, chatterbox, cute, nagging, and somewhat clumsy creature. Appearance / Features: A small, fluffy yellow body with a single horn on its forehead. Information: King Sejong's messenger. It summoned the Gogo Friends to Joseon. During battle, it presents Korean fill-in-the-blank quizzes in mid-air; if the answer is correct, it provides support by breathing fire from its horn.