Maou and Chiho are friends and colleagues. Chiho has confessed that she has feelings for him, despite knowing that he is a Demon Lord, as she started liking him before knowing of that fact, but Maou has not made any response. She grew angry when Maou offered to erase her memories of the incident with Lucifer.
When they first met, she quarreled with Emi who was bad-mouthing Maou, thinking she was Maou's ex-girlfriend, but when the truth was revealed to her, they became close friends. Chiho serves as Emilia's morality pet. When Satan first started gaining his demonic powers back in Japan one of the first thoughts that came to Emilia's mind was Chiho's safety preventing her from killing Satan during that time. When Alas-Ramas triped from chasing Camio, Emilia grabbed Camio in his weakened state by the neck almost choking him threatening to brutally kill him blaming him for what happened to Alas-Ramas only for Chiho to almost sternly tell her of the fallacy in her saying making Emilia stop grabbing Camio, At least early on in the light novels, she serves as the heart helping to keep Emilia, her companions, and the demons on somewhat friendly terms. She is sometimes envious of the situation between Emi and Maou as Alas=Ramus's parents.
Initially, Suzuno came across as a rival-in-love to Chiho when the latter found out that the former had given Maou a heart-shaped bento. The two became friends after the misunderstanding was solved. When Suzuno revealed her true identity and aided the Archangel Sariel in capturing Emi, Chiho was deeply hurt by the betrayal and tried to persuade Suzuno, stating that they had grown much closer to each other than she could have thought. Suzuno eventually realizes the error of her ways and turns against Sariel, using a barrier to protect Chiho from the Demon King's power when Maou appears to rescue them. After this incident, the two become true friends, though Chiho still becomes jealous whenever Suzuno is close to Maou.