On a chilly Christmas Eve, the exorcist Evan comes upon a small and unkempt demon peeping in on a family's Christmas festivities. Rightfully leery of exorcists, the demon panics and attempts to run away. However, enamored by her childlike appearance and mannerisms, Evan decides to drag her to his home. The terrified demon—now named Lily—begs for her life, but to her surprise, Evan washes her and treats her gently. When he is done, he presents a holiday meal and finally a teddy bear to her as a gift. Touched by the kindness that Evan shows, Lily discovers that relationships with humans aren't always volatile, and the pair's bond quickly begins to grow. [Written by MAL Rewrite]