Unnamed Parents[]
Natsumi grew up at the whims of an abusive mother who would constantly starve and berate her. Natsumi was absolutely terrified of her mother, oftentimes being left fearing for her life. Despite this though, she still desperately craved her mother's affection, which is what stopped her from simply running away. However, after her mother ordered her to start working as a prostitute, Natsumi finally snapped and stood up against her tormentor, saying no one would pay because she looked like her. This enraged her mother to the point of choking her, and she likely would have died had Mio not turned Natsumi into a Spirit. Afterward, Natsumi took revenge on her mother by transforming her into a frog. She even briefly considered killing her mother, but she ultimately relented. While feeling momentarily triumphant, she began to cry because what she really wanted was just motherly love.
Even now, Natsumi appears to be traumatized by the events of her childhood, being unable to properly remember her mother's face and name. Her mother's frequent insults of her being ugly also seem to be partly responsible for the negativity bias Natsumi displayed upon her debut. After remembering her past, Natsumi endures her mother's ghost continuing to disparage her, but she overcomes the cruel words to save her friends from <Beast>.
Natsumi's relationship with her father was basically non-existent, as he had already been gone for as long as she could remember. He at least sent the family payments to support her, although he only did so to avoid a scandal. By the time of his death, Natsumi couldn't even recall his face.
Shido Itsuka[]
In the beginning, Natsumi held one-sided hateful resentment towards Shido, but she has since mellowed out and has affectionate feelings for him.
While their first meeting was originally going smoothly, Natsumi turned hostile when she believed Shido discovered her true form, so hostile in fact, that she tried to ruin his reputation and erase him and his friends in a twisted game. Later, after he saved her from Ellen and tried to convince her that her true form was already cute, she gradually opened up to him. She had shown remorse over what she put him through. However, when Shido remembered being nearly killed by being shot, frozen, eaten, incinerated, blown away, or attacked by a huge mob, he considered her actions to be mere childish pranks, surprising Natsumi about his experiences. Shido currently treats Natsumi as one of his friends.
Yoshino Himekawa[]
At first, Natsumi simply used Yoshino's puppet, Yoshinon, as her disguise during her "game", with her impression being good enough that Yoshino never noticed the difference, and she later sealed her into <Haniel> without her noticing. It is later revealed that Natsumi was also jealous of Yoshino because of her cute appearance.
Natsumi thought that Yoshino and the other Spirits would hate her for her previous actions. However, when she posed as Kotori and asked them about it, it turned out that they were all willing to forgive her and would like to know her better, much to Natsumi's shock and disbelief.
After Natsumi's Reiryoku was sealed by Shido, the two of them became good friends due to their similar personalities, and the fact that they don't go to school and stay home together. Natsumi once blurted out a desire to marry her, and even reluctantly agreed to attend Kotori's school to be with Yoshino. Natsumi has become very protective of Yoshino, as seen when she uppercut Shido when she believed he sexually harassed her. However, in turn, Natsumi often hides behind Yoshino if she is scared of someone like Miku for example. Overall, Natsumi is often moved by Yoshino's kindness and views her as a beautiful goddess.
Kotori Itsuka[]
Aside from Yoshino, Kotori is the Spirit Natsumi is closest to. Unfortunately, much of their interactions stem from Natsumi pranking Kotori. While this started with Natsumi making fun of Kotori for being "underdeveloped" for her age while in her adult form, over time she seems to have begun to genuinely enjoy teasing her.
Miku Izayoi[]
Initially, Natsumi viewed Miku as another pawn in her game and took particular delight in terrifying her. However, Miku soon reveals that she holds no grudge against Natsumi for doing so, as Miku relates that she did similar violent actions when she still had full access to her powers.
After being sealed, Natsumi regards Miku as dangerous for her yuri personality. However, Miku still makes an extreme effort to befriend her, and she often clings to Natsumi whenever excited. During Mana Research, the two of them went shopping together after Miku said that Shido and Yoshino might compliment her if she wore new clothes.
Nia Honjo[]
Out of all of the other Spirits' pasts, Natsumi's story in particular resonated the most within Nia's heart, especially with Natsumi's words of wanting to teach Nia how beautiful friendship can be. After Nia is sealed, she is impressed by Natsumi's drawing skills and approaches Natsumi about possibly working for her as an assistant. However, Natsumi remains hesitant about the offer, especially since Nia made it in her usual teasing manner.
