Toujou Household
Basara Toujou[]
Celis and Basara are close childhood friends, who she had visited and trained with whenever she would visit the Hero Clan in Japan. She also never held a grudge against Basara for using his Banishing Shift to eliminate all of the corpses of their friends after Seito was possessed by the evil spirit in Brynhildr despite being sad about losing her friends. She showed serious concern for Basara who had been forced to return to the Hero Clan and being judged as a serious threat to the point of even using her connections to the Vatican to assist her friends. In spite of Celis' initial reluctance to do so, she decided to fight against Basara in order to save them. After Shiba’s defeat, she prepares to move into the Toujou house. She observes Basara’s sexual activity with Mio and Chisato, eventually leading her to become Basara’s final servant. She finally confessed her feelings for him, in return they kiss passionately, she also gives Basara fellatio alongside Nanao and Maria. When they tie the vow, Basara makes Celis first sex anal, since it would defile her morals and makes her a better servant. She later becomes Basara’s wife along with the other girls.
Yuki Nonaka[]
Celis and Yuki are close childhood friends, whom she shows concern for after the Elders decided to use her and Kurumi as sacrifices. During the incident with Shiba, she arrived to assist her in fighting against Shoko despite it potentially being viewed as a betrayal to the Hero Clan using the power of demons. They later become Basara’s wives.
Kurumi Nonaka[]
Celis and Kurumi are close childhood friends whom the latter refers to as "Celis-nee", who she showed concern for after the Elders decided to use her and Yuki as sacrifices.
Mio Naruse[]
Though Mio is viewed as being one of their most dangerous enemies, Celis hasn't shown slight hate or animosity towards Mio as The Elders or other heroes had before.
Chisato Hasegawa[]
Due to her status as a god, Celis has shown to have a great deal of respect towards Chisato, which is mostly due to her being from a religious home. In Volume XII, Chisato encourages her to tie the vow with Basara while they take a bath. Celis then witnesses Basara having sex with Chisato from behind.
Shiba Kyouichi[]
Celis has shown to be mistrusting and almost fearful towards Shiba the same as Basara and even Takashi, in spite of the latter originally being in the same team as him. Like both Yuki and Kurumi, she didn't even hesitate to point Georgius towards Shiba after making it seem as if he were about to kill Basara. This mistrust continued to grow as she witnessed him threatening to kill both Yuki and Kurumi under orders of The Elders, as well as stealing the Four Gods aside from Byakko and even her Georgius.
Hero Clan
Takashi Hayase[]
Celis and Takashi are close childhood friends who have shown to be rather close to one another, and the latter even arrives to rescue her from being killed by Shiba. Both of them later arrived in the dimension to assist Basara and the others, as well as defeat Shiba.