Emi Yusa
Upon their initial encounter, Suzuno and Emi misunderstood each other. Emi had thought that Suzuno, like Chiho, had romantic feelings for Maou and had indirectly informed her about Maou's dark past. In actuality, Suzuno was actually spying on Maou thus forcing her to spend time at his home. After getting on the same page with each other Suzuno and Emi both team up with the focus of bring the devil down. They eventually develop a close bond and later become very good friends to the where they are willing to die protect one another. It can be noted that their takes on justice contrasts greatly. While Emi believes taking lives is cruel and unjust, Suzuno believes that it is necessary and usually unavoidable.
Sadao Maou
Suzuno was originally meant to spy and assassinate the Demon King under the orders of the Church. However, having spent time with his entourage and ultimately being saved by him, she realizes that Sadao is no longer the villain that he once was since living on Earth and becomes a trustworthy ally and friend.
Chiho Sasaki
As an inhabitant of earth, Suzuno initially saw Chiho as someone who should have her memories involving Ente Isla erased.