Sanjouno Haruhime[]
Mikoto has been friends with Haruhime since childhood. Mikoto and the other members of the Takemikazuchi Familia would often sneak Haruhime out of her manor at night to play as thanks for her request to have food sent to their shrine. Even when Haruhime's father stopped sending assistance due to his dislike of them, Mikoto and the others kept coming to see her until her father disowned her.
After learning that her friend was in Orario and of her plight, Mikoto was determined to rescue her. She became enraged when she discovered the plan to have Haruhime's soul sealed within the Killing Stone and, along with Bell, resolved to save her, despite the consequences. Mikoto even went as far as deliberately using Ignis Fatuus on herself in order to take out several Amazonesses guarding Haruhime and to give Bell a big enough distraction to destroy the Killing Stone.
Mikoto cares a great deal for Haruhime's well-being, usually being nearby and protecting her during adventures in the Dungeon. She even received her status from Takemikazuchi with the purpose of saving Haruhime from her loneliness. After she discovered Haruhime's situation, Mikoto's earnest wish was to see her friend smile as she used to, becoming tearfully happy when Haruhime was finally able to do so.
Takemikazuchi[]
Takemikazuchi was Mikoto's God, and she was a member of his Familia. He has known her since she was still a child back in the Far East. He took the role of a parental figure toward Mikoto when he understood her desire for a family, especially for a father.
Mikoto originally loved and respected Takemikazuchi as if he was her own father. However, her love for him soon became that of a lover. She loves him romantically and is often shown to be jealous when she sees him with another woman.
During a celebration for the anniversary of Takemikazuchi's arrival on Earth and Mikoto's departure from the Familia, Takemikazuchi gave her one half of a set of short swords, promising to give her the other the day she returned to his Familia. The act moved Mikoto to tears, envisioning that the day the two swords are reunited would be the day she would confess her feelings to him.
Kashima Ouka[]
Mikoto and Ouka grew up together in the same orphanage in the Far East. They became like a family, eventually becoming members of the Takemikazuchi Familia. They are able to effectively fight as a team, even after Mikoto converted to the Hestia Familia. Mikoto has a lot of trust in him and follows his orders, such as when she agreed to perform a Pass Parade on Bell's party for Chigusa's sake, though she hated doing so. She also gets annoyed with Ouka due to his failure in noticing Chigusa's feelings for him.
Hitachi Chigusa[]
Like with Ouka, Mikoto and Chigusa grew up together in the same orphanage and became members of the same Familia. The two are very close friends and deeply care for one another, being able to still fight as a team after Mikoto left the Familia. Mikoto agreed to perform a Pass Parade on Bell's party after Chigusa was badly injured, although she did it reluctantly. Though normally shy and timid, Chigusa becomes more open when talking to Mikoto. Mikoto also tries to help Chigusa get her feelings noticed by Ouka, but to no avail.
Bell Cranel[]
Mikoto first encountered Bell when her Familia performed a Pass Parade at his party. After Takemikazuchi told Hestia what happened, Mikoto, alongside Ouka and Chigusa, were selected to go help find him. Upon doing so, she expressed her remorse.
After Apollo had set his sights on Bell, Mikoto came to the boy's aid by fending off other adventurers. Still, Mikoto felt immense guilt from the Pass Parade and felt she had done nothing to atone for her actions. She asked Takemikazuchi to allow her to leave the Familia and join Hestia's for the upcoming War Game, to which he agreed.
Mikoto respects Bell and obeys his orders, as she would with Ouka. Her respect and admiration of him increased when he resolved to save Haruhime from the Ishtar Familia, despite the consequences. She went along with him in sheltering Wiene and protecting the other Xenos while they made their way back to the Dungeon.
Hestia[]
Hestia was initially very upset with Mikoto, as her Former Familia used a Pass Parade on Bell's party, trapping them in the Dungeon. She said that if Bell died, she would hold a grudge against them, but wouldn't hate them, and asked for her help in rescuing Bell. It seems her feelings towards her had subsided after the events on the eighteenth floor, as Hestia accepted Mikoto into her Familia in preparation for the War Game.
The two now have a good relationship. Hestia finds her cooking delicious and says Mikoto would make a good wife. She also supports her and her love for Takemikazuchi.