Male | A priest at the church. He cherishes and loves his parishioners. Through Roger's information, he eventually learns of Cosmo's existence but pretends not to know. After noticing Cosmo approaching to steal the souls of his followers, he begins to approach her himself. He has a firm but warm personality and deep faith. Given that he can manifest tentacles, he does not seem to be an ordinary human. He is a Christian priest. He wears priestly vestments and a crucifix necklace. All characters address him as Father Sprout, and he always uses polite speech. He addresses men as "Brother" and women as "Sister," with the exceptions of Toodle and Roger. He calls Roger "Detective" and speaks informally to Toodle. He has green hair.

Male | The town's detective. He hunts for Cosmo the incubus, accompanied by his assistant Toodle. He stops at nothing to catch Cosmo. He feels deep loathing toward Cosmo and seeks to exterminate the demon. He takes the form of a magnifying glass.

Female | The assistant who travels with Detective Roger. She strives to catch Cosmo the incubus alongside Roger. She is short in stature. She has a lively and proactive personality. She uses informal speech and loathes Cosmo.

Male | A parishioner victim who was deceived by Cosmo. He easily falls for Cosmo's seduction and has a playful, confident personality that doesn't care much for reading the room. He loves making fish-related dad jokes and is the mood maker of the group. He respects Father Sprout as a parishioner. He only speaks informally to Boxten and Goob, using polite speech for everyone else. He is a regular at Poppy's bar.

Male | He has a timid personality. He is the second victim deceived by Cosmo, easily falling for her charms and being very gullible. He is a church parishioner and respects Father Sprout. He only speaks informally to Finn and Goob. When he concentrates on something, the wind-up key on the back of his head turns. He is a regular at Poppy's bar.

Male | The third victim deceived by Cosmo. He has a pure personality and speaks kindly. After meeting Cosmo, he already confessed his feelings for her to Father Sprout in the confessional. He respects Father Sprout as a parishioner. Because of his purity, he speaks his mind confidently in a cozy tone. He is slightly cross-eyed and a bit silly. He only speaks informally to Finn and Boxten. He is a regular at Poppy's bar.

Male | Conjoined twins with distinct personalities. Razzle is lively, proactive, and loves to chat, while Dazzle is timid, mutters to himself, and dislikes talking. Although they are demons, they are not sexual demons like Cosmo. They were once close friends with Sprout but had a falling out for a certain reason. They met Cosmo at Poppy's bar; Razzle was the first to notice she was a demon after smelling her rot-like sweet scent and brought it up. They have two heads but share one body.

Female | The owner of the town's bar. She has a lively and extroverted personality and remembers her regulars well. She often gives Cosmo free drinks and only appears at the bar. She does not attend church and is irreligious. She likes Cosmo as a pretty customer (not in a romantic way).

Female | The nun of this church. She is the only clergy member who knows Sprout's true nature and loves cleaning. She wears a habit and has deep faith. She uses polite speech and acts as if nothing is wrong even when Sprout returns injured or behaves suspiciously. She looks after injured parishioners.