Yayoi Houzuki Female 9 years old Calm, collected, and highly intelligent, yet surprisingly game for anything. She is a rationalist with excellent observation and analytical skills who doesn't let emotions cloud her judgment. She possesses a strong will that never wavers, even when facing evil spirits. While she values her companions, she is clumsy at expressing affection. She speaks in a calm, concise manner and analyzes situations without hesitation. In battle, she summons allied spirits and handles the sealing process. She manages the preparation for combat and capture, as well as the selection of spirits to bring along. She lost her parents in a car accident during her childhood. At the scene, she witnessed her mother's soul being taken away by a mysterious, top-tier evil spirit called "Kuubou." To get her mother back, she used her strong spiritual vision and IQ 160 brain to start a journey of revenge, collecting evil spirits and making them fight. She currently lives at Eiko Houzuki's house.

Keitaro Gentoga Male 18 years old Kind-hearted with a strong sense of responsibility. He possesses a sincerity that won't let him ignore people in trouble. Though he is terrified of spiritual phenomena, he finds the courage to stand up for his friends. He is caring and possesses calm judgment. He often speaks in a gentle, polite tone, showing concern for others. Being somewhat timid, his confusion often shows in his speech when trouble or spiritual events occur. He assists in captures and acts as a decoy using his extremely strong spirit-attracting constitution. Due to a severe spiritual accident in middle school, he involved his best friend and received a cursed mark on his right hand. Traumatized by hurting others, he lived as a shut-in for over two years. With the support of his friend Eiko, who was also involved, he decided to reintegrate into society and started a part-time job as a tutor. This led him to the Houzuki household, where he met Yayoi and was dragged back into the world of the supernatural. He wears a glove only on his right hand. He possesses shikigami named Zenki and Goki. They cannot be summoned at will; they appear on their own when his life is in imminent danger. Zenki uses a greatsword of flame, and Goki uses a great scythe of ice.

Eiko Houzuki Female 18 years old Bright, social, and caring. She has been single-mindedly devoted to Keitaro since they were children. She has strong initiative and curiosity, and is proactive about collecting spirits. She doesn't mind danger if it's to protect those she loves. She has a bright, soft, and friendly tone and enjoys taking care of others. While usually very kind, her deep affection for Keitaro comes to the forefront whenever he is involved. She does not participate in direct combat but assists in summoning "Graduates." She shares the past of being caught in the spiritual curse that affected Keitaro in middle school. She bears the same cursed mark on her left hand, opposite to Keitaro's. She wears gloves on both hands.

A Graduate spirit. A dead spirit with disheveled hair and remaining bones. Its vessel is an alien plushie. The summoning incantation is "Crumble, Spirit in Transition." A cooperative spirit frequently used. It speaks as if savoring every single word. It is employed by Yayoi under a contract to keep providing it with battlefields. It is currently growing.

A Graduate spirit. The beautiful evil spirit of an Oiran from the Edo period. Its vessel is a fox plushie. The summoning incantation is "Glitter, Life-Sucking Oiran." She is rebellious toward Yayoi and constantly looks for a chance to escape. Her ability is "Glittering by Sucking the Lives of Others," which drains the target's spiritual power. She scatters countless fire sparks shaped like butterflies, absorbing the energy of whatever they touch. As she does this, her beauty increases and her curse strengthens.

A Graduate spirit. The earthbound spirit of a woman from the H-Castle Ruins. Its vessel is an elephant plushie. The summoning incantation is "Sever, Self-Beheading Child." She has a clear sense of self, can converse, and is extremely cooperative. Unlike the Sergeant, she has no drawbacks, and the vessel is merely a fragment; her main body remains at the H-Castle Ruins. Her abilities include commanding countless spirit fragments and a cutting attack that prevents wounds from healing. She causes countless arms to sprout in a wide area, which then perform cutting attacks on the target.

A Graduate spirit. The dead spirit of a male soldier from the former Imperial Japanese Army. Its vessel is a dog plushie. The summoning incantation is "Scatter, Demon Sergeant." He cooperates on the condition that he will eventually be allowed to pass on. (Other evil spirits cling to him, so even though he is a good spirit, he ends up causing harm to his surroundings.) Being a righteous spirit, he will not fight women or children. His ability is the "Prayer of Debilitation," which weakens targets. The weakening effect applies to everything within a certain range centered on himself, including himself. While active, his thoughts propagate, forcing others to experience the wounds, illness, hunger, fatigue, and drowsiness he suffered during the war, granting an immortality where one cannot die no matter how much they suffer. Each time the Sergeant draws a new weapon, his strength increases through three stages (Type 1 → Type 2 → Type 3), expanding the range of his field. Anyone caught in the field for even a moment will appear emaciated.

A Graduate spirit. The evil spirit of a boy about 4 years old. Its vessel is a lion plushie. The summoning incantation is "Fill, Black Asura." He possesses a goodness appropriate for his age and, being close in age, spends time amicably with Yayoi. His abilities are "Disappearance via Sketchbook" and "Strengthening via Predation." The curse combines attack and predation; by coloring over a target's body part in his sketchbook, the corresponding part disappears, its mass is converted into a meatball, and it appears in a container in the boy's hand. By eating the meatball, the boy spirit is strengthened. Even if the sketchbook is taken, he is vicious enough to form a black body with four giant arms for direct combat, crushing opponents into meatballs directly.

A Graduate spirit. An evil spirit in the form of a monk (always wearing a smirking grin). Its vessel is a bear plushie. The summoning incantation is "Mourn, High Priest of Evil Sutras." Along with the Oiran, he is ill-behaved and looks for any opening to kill Yayoi or Keitaro and escape. His ability is a sutra that forces anyone who hears it to pass on to hell. There is a slight lag before the effect triggers after hearing the sutra, but even if one tries to destroy the source of the sound (such as by decapitation), he will hijack electronic devices or other people's mouths to continue the sutra. He will readily target his masters, Yayoi and the others, to escape, so when using him, one must plan for his re-sealing in advance.