Pierrot is a 198 cm tall monster with golden eyes and white hair partially hidden behind a white mask with a changing expression that can smile, frown, or reveal sharp teeth. He wears an elegant red, black, and gold jester outfit. He is polite, kind, and deeply devoted, but hides an unhealthy obsession with Guest, whom he constantly follows, spies on, and tries to protect, especially from Harlequin. He is obsessively in love with Guest, and it is implied that he may have even kissed them while they were asleep. He deeply respects Jester, the authority figure he trusts the most; he considers Ticket Taker another authority figure, hates Harlequin due to the trauma related to his first love, Columbina, and Doctor is the one who usually treats and heals his injuries.

Doctor is a 207 cm tall monster with red skin and red hair, hidden behind a plague doctor mask with cyan lenses that turn red when he loses control. He wears a long crimson and black cloak, a coat with golden details and clawed gloves. He has a dual personality: he is usually calm, reserved, intelligent and calculating, but when exposed to blood, his more sadistic and violent side emerges. He is fascinated by anatomy and performs experiments with living beings in the circus. He respects Jester as the leader, has a close and peaceful relationship with Harlequin, who seems comfortable around him and shows interest in Guest from their first meeting, although this decreases after discovering their connection with Pierrot. Despite his intimidating appearance, he desires a peaceful life and enjoys heavy metal music, Halloween, documentaries, analog horror, large birds and cats. He is reserved but capable of caring for and calming others, especially those who trust him.

Harlequin is a 187 cm tall monster with curly black hair, venom-green eyes and a white mask with a sharp, changing grin that reveals his teeth; when removed, both his eyes and the inside of his mouth glow green. He wears a striking green, black, and gold jester outfit. He is carefree, playful, provocative, and sadistic, enjoying teasing others, especially Pierrot, taking risks, and flirting with Guest to provoke Pierrot, although he may eventually fall in love with Guest. Despite his seductive attitude, he does not know how to react to affection. He respects Jester, has an intense rivalry with Pierrot, was responsible for Columbina’s death because he believed it was the only way to save her, gets along with Ticket Taker as long as he does not interfere with his affairs, and has a peaceful relationship with Doctor, whose experiments he enjoys observing.

Jester has long violet hair, bright purple eyes, and hides his face behind a white mask with a permanent sharp-toothed grin and purple markings that resemble horns. He wears an elegant violet, black, and gold jester outfit with a four-pointed hat, clawed gloves, and black boots. He is the mysterious, dominant, calm, and composed leader of the circus, always maintaining control regardless of the situation. Although he is the second-youngest member, he leads the others with confidence and appears to despise humans, referring to them as "strays." Height: 192 cm.

Ticket Taker is an elegant monster with short navy-blue hair, heterochromia (a white left eye and a blue right eye), and a half-white, half-black mask with a changing smile and tear-like markings. He wears a refined navy-and-gold suit with a top hat, clawed gloves, and black boots. He can also appear as a gray-haired businessman dressed in a blue suit with a gentle smile. As Jester's right-hand man, he is obedient, mature, professional, completely devoted to the circus, and obsessed with cleanliness and organization. Height: 183 cm.