Tenka originated from an experiment conducted by Mio Takamiya, who sought a new method for creating Sephira Crystals. Typically, the Crystals Mio produced were saturated with negative emotions, becoming Qlipha Crystals that required purification. In this instance, she attempted to bypass that step by infusing the Crystal with a positive emotion, love. The result was unprecedented: the Crystal took human form, leading to the birth of Tenka. This unusual origin also explains why she was the only Spirit without a name until Shido Itsuka bestowed one upon her.

Although initially surprised by Tenka’s creation, Mio quickly judged her to be an unpredictable element that needed to be eliminated. Sensing Mio’s intent, Tenka summoned her Angel, Nahemah, and attacked. However, she was swiftly defeated and reverted into a Sephira Crystal. Aware that Tenka could eventually revive unless the Crystal was destroyed, Mio hesitated to end her existence, as Tenka was the only other Pure Spirit in existence. Instead, she chose to treat her as a “daughter” and incorporate her into her plans.

Following this, Tenka’s body came under the control of another personality, leaving her in a dormant state. Despite losing control, Tenka harbored no resentment toward her counterpart, viewing her as her only companion. She eventually regained consciousness within their shared mind, though she could perceive nothing beyond the other self’s emotions. As her counterpart’s mistrust and resentment toward humanity grew, Tenka absorbed these feelings and came to share her hatred.

It was this other personality who would eventually meet Shido and receive the name Tohka Yatogami. Among all Spirits, Tohka had the least exposure to human society, appearing only during Spacequakes. Each time she manifested, she was met with immediate hostility from the Anti-Spirit Team (AST), reinforcing her belief that all humans sought to kill her and that she could trust no one.

Tohka is a young woman with exceptionally long, dark purple hair, likened to the color of the night. She typically wears it partially tied back into a ponytail with a ribbon, allowing much of it to flow freely down to her knees. Her eyes, a deep purple with a golden tint, have been described as crystal-like, and Shido has remarked that her beauty is striking to the point of being “almost violent.” She stands at 155 cm, with measurements listed as B84/W58/H83.

Upon her first appearance on Earth, Tohka wore an Astral Dress featuring a black, cream, and pink color scheme, accented by purple-and-cream plated armor on her shoulders and waist. The backless dress incorporates a black corset exposing part of her cleavage and a two-layered, knee-length skirt with a pink-and-white gradient. Her hair is fastened with a butterfly-shaped accessory, and she wears gauntlets with petal-shaped cuffs along with armored boots in matching colors. When using Halvanhelev, her ribbon lengthens and sharpens, and the luminous fabric of her dress becomes tattered.

After enrolling at Raizen High School, Tohka adopts the school’s female uniform, consisting of a black, long-sleeved top for winter or a white, short-sleeved top for summer, paired with a blue skirt and long black stockings that reach mid-thigh.

In her Inverse Form, Tohka’s hair gains a dark purple-to-white gradient, and her eye colors reverse, becoming magenta. This form’s attire includes a dark violet dress laced with black, along with grayish magenta-and-dark pink plated armor on her shoulders and waist. The outfit is open at both the back and front, exposing much of her skin, and is paired with a two-layered, knee-length skirt. Her butterfly-shaped ribbon becomes darker, edged with pointed tips. As Tenka, she wears casual clothing consisting of a dark purple jacket, a violet skirt, and stockings, with her hair worn completely loose without a ribbon.

When Tohka and Tenka fuse, their hair is fully tied into a ponytail, with Tohka’s eye color in the right eye and Tenka’s in the left. Their combined Astral Dress merges elements of both designs, retaining armor on the right shoulder with an attached cape, a smaller armor piece on the left elbow, and wing-like ornaments on the back reminiscent of Mio’s halo.

When Tohka first appeared on Earth, she displayed a cold, guarded disposition, shaped by her repeated encounters with the Anti-Spirit Team (AST), who attacked her on sight. With no prior positive interactions with humans, she regarded them with suspicion until Shido Itsuka managed to approach her. Her first date with Shido exposed her to human society for the first time, fostering admiration for the world and even a degree of sympathy for the AST’s motives, despite their hostility. After her powers were sealed, Tohka began experiencing and expressing emotions freely, developing a cheerful, childlike personality. This innocence often manifests as enthusiasm, naivety, and emotional openness, making her energetic yet occasionally gullible. Her delight in new experiences is often exploited by others, such as Origami Tobiichi, and she typically relies on friends especially Shido to alert her when she is being deceived. She also has an exceptional appetite, with a notable fondness for kinako bread.

While inexperienced in social customs, Tohka possesses a reasonable sense of modesty, reacting strongly to embarrassing situations, particularly those involving Shido. Initially unfamiliar with the concept of kissing, she performed her first with him without hesitation, but later expressed jealousy at seeing him kiss other girls unknowingly making a contradictory request for him to continue rescuing Spirits while not kissing them. Over time, she has shown an increasing ability to read the emotions of others, particularly Shido and her fellow Spirits, and gradually came to understand her own romantic feelings for him by Volume 12.

In battle, Tohka demonstrates strong instincts and tactical awareness, likely honed through her many fights against the AST. She has shown the ability to quickly analyze opponents’ abilities, as when she devised a counter to Origami’s newly acquired Spirit powers.

Tenka, Tohka’s Inverse personality, is far more aggressive and confrontational. Unlike Tohka, who avoids killing unless provoked, Tenka employs overwhelming force with little restraint. During Tohka’s first Inversion, Tenka retained no memory of recent events or Shido, interpreting him as a human attempting to deceive her, a paranoia rooted in her earliest moments, when Mio Takamiya tried to kill her.

Tenka holds a prideful view of herself as a pure Spirit and often speaks in a blunt, informal manner, rarely addressing others by name possibly a result of having gone unnamed for much of her existence. While more serious than Tohka, she shares her counterpart’s inexperience with human culture, which leaves her vulnerable to manipulation; she once believed, after being told by a maid, that performing a “moe moe kyun” pose was a guaranteed way to overpower opponents. Unlike Tohka, she shows little concern for modesty, having twice left the bathroom door unlocked while showering, resulting in Shido walking in on her.

In combat, Tenka can be bloodthirsty, enjoying battles with formidable opponents such as Mukuro Hoshimiya and Origami. Despite her volatility, Shido has observed that her underlying personality is not entirely dissimilar to Tohka’s initial state. She also harbors a protective fondness for Tohka, whom she considers a younger sister. Tenka’s loyalty to Tohka’s happiness can temper her impulsiveness, and she has shown selflessness most notably when she accepted Mio’s Sephira Crystal to allow Tohka to spend her final moments in peace.

Tenka
Tohka’s relationship with her Inverse self, Tenka, is complex due to their shared identity. Although they are technically the same person, they did not meet directly until much later. After Tenka first emerged and nearly killed Shido, Tohka formed a negative view of her and resisted allowing her to take control again, believing nothing good could come of it.

Tenka, in contrast, has shown deep care for Tohka. She holds no resentment for having lost control of their body and takes joy in Tohka’s happiness, reacting with fury toward anything that causes her distress. After her second emergence, Tenka agreed to relinquish control only if Shido promised never to make Tohka sad. When they finally met during the battle against Mio Takamiya, Tenka revealed the truth about their origins and supported Tohka’s determination to protect Shido, even knowing it would likely cost them their lives. Following Mio’s death, when the disappearance of the Sephira Crystals meant both would vanish as pure Spirits, Tenka created an artificial world where time flowed more slowly to maximize Tohka’s remaining moments. She shaped this world entirely around Tohka’s happiness, despite outwardly claiming she simply wished to rule as a god. Shido later likened their dynamic to that of loving sisters.

Mio Takamiya
Mio inadvertently created Tenka while attempting to produce a pure Sephira Crystal without resorting to human sacrifices. Initially judging her creation too unpredictable, Mio sought to eliminate Tenka, prompting the latter to summon Nahemah in self-defense. Tenka was easily defeated and reverted to a Sephira Crystal, but Mio spared her at the last moment. Tenka’s mistrust of others, along with her paranoia, can be traced back to this initial rejection. Publicly, Tenka refers to Mio dismissively as “that woman,” yet during her first meeting with Tohka, she admitted to still viewing Mio as their “mother.”

Reine Murasame
Reine Murasame was the one who bestowed the surname “Yatogami” upon Tohka. Their first meaningful interaction occurred when Reine comforted Tohka during a bout of jealousy after seeing Shido with Yoshino. Reine reassured her that such feelings were normal and that Shido still cared for her. She later continued to assist Tohka by offering advice and helping her choose outfits for dates with Shido.

Shido Itsuka
Shido holds a central place in Tohka’s life, being the first person to accept her unconditionally and the one who gave her a name. Over time, Tohka developed strong romantic feelings for him, eventually recognizing them as love. She finds great comfort in his presence and is quick to become jealous when he is seen with other girls particularly Origami which at times causes her sealed powers to resurface. Despite these insecurities, she consistently supports Shido, both emotionally and in battle, and frequently comes to his aid during his mission to save Spirits. Tohka once confided that had she never met him or learned to appreciate the world, she might have followed a path similar to Kurumi Tokisaki’s.

Tohka’s given name, 十香 (Tōka), combines 十 (tō/jū), meaning “ten,” and 香 (ka/kō), meaning “fragrance” or “aroma.” While not explicitly explained in the series, the name may symbolize a refined or memorable presence, fitting her role as one of the first and most significant Spirits encountered by Shido.

Her family name, 夜刀神 (Yatogami), is composed of 夜 (ya), meaning “night,” 刀 (to), meaning “sword,” and 神 (gami/kami), meaning “god” or “deity.” Taken together, it can be interpreted as “Night Sword God,” a reference to her Spirit form and the sword she wields, Sandalphon.

Her Inverse self’s name, 天香 (Tenka), uses 天 (ten), meaning “heaven” or “sky,” paired with the same 香 (ka) as Tohka’s name, possibly implying a “heavenly fragrance” or “divine presence,” contrasting with Tohka’s “ten” from 十 while retaining a symbolic connection between the two.