Nia Teppelin (ニア・テッペリン Nia Tepperin?) is the disowned daughter of Lordgenome. She is also an artificial being made by the Anti-Spiral and serves as the main antagonists' messenger in the third act. She is Simon's main love interest and eventually marries him in the epilogue before she fades away.
Nia is a delicate-looking young girl of average height with curly, light blue/pale blonde hair. Her initial appearance shows her to have extremely long hair running down her back until it is one day ruined during the gunfire of battle (Caused by Yoko pretending to shoot her in the head but missing on purpose to hit the gunmen's shoulder). She later asks Yoko to cut it to just above her shoulders. She has peach skin and unique blue eyes with pink crosses ("+") for pupils (Designed to look like flowers). She wears a variety of outfits, mostly pink and white.
In Part Two she looks mostly the same, but her features have matured, gaining womanly curves. Her hair has become straighter and returned to its old length. As usual, she wears a white and pink dress, along with the ring Simon gave to her when he proposed. After the Human Extermination System is activated, her skin becomes covered with red circuit lines and her eyes gain a flat, darkened tone. Her dress is eventually replaced by a skintight bodysuit covering everything up to her head; the suit itself is black with red circuit lines and asymmetrical turquoise highlights.
Upon being recalled to the Anti-Spiral homeworld, Nia's eyes return to normal, but her outfit remains the same. When Team Dai-Gurren frees her, her bodysuit dissolves, but Simon catches her with his longcoat, which she wears for the rest of the battle. After her return to Earth, she is given a white wedding dress for her marriage to Simon.
From her first appearance and for most of the first arc, Nia wears a pink outfit with a skirt and a gold neckpiece with a red tie hanging from it. When the team arrive at the beach, she wears a white swimsuit. After the timeskip she wears a long, flowing pink dress. When she changes to her Anti-Spiral persona, she wears a skintight bodysuit with Anti-Spiral markings on it. She continues to wear this until the end of the final episode. When she returns to Earth she is briefly seen in a pink outfit simialar to her normal one but without sleeves. During the wedding, she wears a white wedding dress with a thin veil prepared by Old Coco.
Nia is a sweet, kind and caring girl by nature. She always likes people to be happy and is highly empathetic to others, especially Simon. She naturally tried to cheer up Simon when he was distressed over Kamina's death but unknowingly made him worse and upset Yoko to the point where she shouted at her and stormed off. She is never intentionally mean and almost always has a smile on her face even when she was fading away in the last episode of the series.
Through her travels with Team Dai-Gurren, Nia opts for a change in her personality a little. She eventually follows Kamina's words and believes in Simon with her entire being. Also in her travels, she shows a rational thought process similar to Yoko and is very willing to stand up against the odds when need be. Likewise, she is a bit rash though and will not hesitate to throw herself into the fray to try and reason with the enemy. In season 1, she does so three times (though one of them was addressing soldiers about them sacrificing themselves.). In this regard, Nia can often be oblivious to certain words and meanings due to her sheltered life.
For most of the third arc, Nia serves as the messenger from the Anti-Spirals to the humans, during the activation of Earth's Human Extermination System. After the Anti-Spiral data awakens within her and converts her into a Anti-Spiral life form, becoming an emotionless and serious person, the exact opposite of how Nia was beforehand. As the messenger, she wears a dark skin-tight suit, covered with red line patterns resembling a circuit board, and the previously pink irises of her eyes have become black.
Pre-Beastman War arc
Some time before her introduction, Nia lived a comfortable life with her father. This life would soon come to an end, however, when Nia became too self-aware and questioned her father about her existence, prompting him to have her placed in a pod and thrown into a canyon filled with other "failed Nias", where she would be found by Simon.
Beastman War arc
During a battle with some Gunmen, Simon lost control of Gurren Lagann when Lagann detached itself due to Simon's unstable mental state. After falling into a canyon, Simon found Nia's pod and opened it with the Core Drill. Nia stepped out, surprised to see something other than a Beastman and was told about what a human was by Simon. Nia and Simon were then attacked by a Beastman, Simon prepared to stay behind to save Nia but was saved by the timely arrival of Kittan and Yoko. She is revealed at the end of the episode to be Lordgenome's daughter and a princess. She was originally disliked by the members of Team Dai-Gurren, (Kittan tried to interrogate her, but failed) but when Adiane the Elegant, one of the Four Generals appears, and reveals she was an exile, the members of Team Dai-Gurren accepted her. After her encounter with General Guame the Steady, she comes to an understanding of the reason Simon found her outside the palace, being forsaken by her father after she started attaining her own will and self-consciousness, as he considered his offspring nothing more than dolls, and decides to join the Team Dai-Gurren as a cook (even though her cooking is unbearable to anybody but Simon and Boota) in order to confront her father. In the final battle with Lordgenome, she boards Lagann with Simon and when she sees Simon losing, says she will believe in him with her whole being. This drives Simon to kill Lordgenome. Nia attempts to save her father from falling, but fails, though this does nothing to shake her resolve, as she states she "will head toward tomorrow".
Anti-Spiral WarSeven years after the war with the Beastmen, Nia receives a marriage proposal from Simon. She refuses at first, after her bubbly contrived logic causes her to misunderstand his words, but after receiving counseling from Kiyoh and Kiyal, she decides to accept. As predicted by Lordgenome, when the population limit is reached, a mysterious force takes control of her body, and her hidden identity as the Anti-Spiral's messenger awakens. Appearing before the population of the planet, she broadcasts the intention of the Human Extermination System, proclaiming that the moon will collide with the Earth in three weeks, bringing the city to a panic. Her body is entirely unchanged, with the only differences being a black skin-tight suit and her narrowed, menacing eyes with dark irises. She reveals to Simon that her memories as a human still remain, but after realizing who she really is and seeing the pointlessness of human progress, her entire personality radically changes and she declares her past as long lost fiction. According to her, the Anti-Spiral's purpose is to bring mankind into ultimate despair by letting them struggle to the very end, right before their inevitable destruction. However, she continues to wear the ring given to her by Simon, and once he points this out, she realizes that unconsciously, her feelings toward him haven't changed. When Simon points out that the true intention of the trial she set up for mankind was to create a resistance against the Anti-Spirals, she reverts to her old self. However, just as he catches a glimpse of the old Nia, she is transported to the Anti-Spirals' home world, and Simon vows to rescue her. When the Anti-Spiral questions her and tries to probe her body, Nia explains that Simon will defeat them. Simon appears and frees Nia, causing her skin-tight suit to dissipate moments before he catches her in his jacket. She appears before Simon several times over the course of the arc, to repeatedly tell him that all efforts against the Human Extermination System are futile while increasing the odds against mankind. But it was when she is the only thing keeping the Gurren Lagann from the "moon's" control system that Simon points out to her that all her actions and appearances before him were in fact the true feelings of her former self, who urges Simon to keep fighting, allowing Nia to have the strength to return to her former self while ending the Human Extermination System. However, she is transported back to the Anti-Spiral home world so the data on Team Dai-Gurren can be extracted from her for analysis, resulting in the rescue attempt that begins the fourth and final arc. She rides in the head of Tengen Toppa Gurren Lagann and helps Simon defeat the Anti-Spirals. Ten days after the return to Earth, she and Simon get married, though she begins to fade away before the shocked crowd but an unsurprised Simon. She tells Simon she loves him and he answers back saying that he will never forget her "till the end of the universe". Nia corrects him, stating it will never end and that's what they'd worked so hard for. She smiles as Simon says he loves her and she fades away.
After Anti-Spiral War Arc
Nia's memorial site is near the graves of Kamina and the members of Team Dai-Gurren who died fighting the Anti-Spiral. Her memorial has the flowers she held at the wedding along with a sword.
Nia is Simon's main love interest, coming into the series the episode after Kamina's death. When Nia and Simon first meet Simon is speechless and Nia is confused as to why he has no beast bodyparts. He informs her it is because he is Human. After bringing her onto Dai-Gurren the crew members aren't sure if they should trust her after it is revealed as Lordgenome's daughter. Simon loves Nia a lot, even going as far as to charge at a Gunmen by himself without Lagann in an effort to save her only to be out run by the other crew members' Gunmen and ending up tripping and twisting his ankle. While Simon fights Lordgenome, Nia puts all her faith in Simon and tells him she believes he can win. After winning the fight against Lordgenome, Nia cuddled up to Simon and Simon put his arm around her.
In Part two Simon and Nia are both more grown up, and Simon asks Nia to marry him, but she turns him down, not understanding what marriage is, but later accepts after an explanation from Kiyoh and Kiyal. Even after it is revealed she is the Anti-Spiral Messenger, Simon stops at nothing to get her back. Once he saves her and the rest of the world they finally get married and Nia smiles and expresses her love for Simon as she fades away.
At first Yoko dislikes and distrusts Nia due to her unusual origin and Nia's thoughtless words about Kamina. As time goes on Yoko comes to trust Nia and the two developed a sisterly bond. When Yoko leaves the capital to travel she tells Simon to take care of Nia. According to the movies, Nia and Yoko kept in contact through letters afterward.
Though Nia never met Kamina, she gains a great care and respect for him through the stories told to her by Simon. Through her belief in Simon she comes to believe in Kamina's philosophies, and in the Gurren Lagann movie is shown to address him while writing in her journal. In the Otoko series and in others where she does know him, they get along well. Kamina is also one of the few who can stomach and enjoy her cooking, the others being Simon and Boota.
Nia has a complicated relationship with her father. For much of her life Lordgenome was the only human she had contact with, all the others being beastman. After traveling with Team Dai-Gurren and seeing the oppression of humans she expresses anger and questions her father when she confronts him. When Simon defeats Lordgenome and throws himself off the capital, she runs and tries to save him, yet sheds no tears and expresses a desire to move forward when he is gone. At the end of the series/movies she shows to still care for him when he sacrifices himself to give team Dai Gurren power.
Nia has never been seen piloting a Gunmen, except when she rode with Simon in the head of Tengen Toppa Gurren Lagann. She doesn't seem to have any fighting ability, as she is easily captured by Guame and his Beastmen. Her only skill seems to be cooking, though she creates monstrosities whenever she attempts to do so. Everyone but Simon and Boota seem to be mortally terrified of her cooking. She is, however, a skilled sports player and won a game of beach volleyball against Yoko.
After becoming the Anti-Spiral's messenger in Part 2, she gained the ability to travel between spatial dimensions, teleport between locations instantly, and intercept most methods of communication. She also has a power involving creating holograms.
In the second film, Nia is given her own personal Tengen Toppa Gunmen, the Tengen Toppa Solvernia. It is shaped like a feminine human body with an energy cascade simillar in color and composition to her own hair. It's weapon is a drill spear and is the first to wound the Grand Zamboa after it tears Tengen Toppa Gurren Lagann apart.
- One minor recurring theme that presents itself during the series both before and after the time-skip was that during the two times she is captured (first by Guame and then by the Anti-Spiral) she keeps a fiercely optimistic attitude (saying with a straight face that she won't die even though Guame has a gun pointed at her face, or courageously declaring Simon won't fail in saving her as the Anti-Spiral starts dissolving her structure) only to tear up the moment Simon comes to save her.
- Nia narrates the next episode previews up until the final episode of season 1. Her quotes are used as the titles for those episodes.
- Another recurring theme is her lack of common knowledge: She misunderstands many of the phrases Kittan used during his "interrogation" during the Beastman War arc, and it continued to years later when Simon proposes to her and turns him down, only to have Kiyoh and Kiyal explain it to her later.
- Gainax has stated that 7 years is a long time, and that Simon and Nia "did what had to be done" during the timeskip.
- Gainax stated that during the 7 years before Season 2, Nia went out and traveled the world "Like a real princess".
- Nia and Simon had exactly 1 week before the wedding and spent it on an island. Gainax made no further comments on why though.
- Gainax also said that Nia held on to her existence with fighting spirit, but eventually her time would come to an end, and things such as her nose or hand would start to disappear and various parts of her would start to wither. This was possibly why she disappeared quickly rather than over time.
- Despite being the Chef, no one seems to enjoy her food except Simon, who enjoys the food, not merely just because she made it, but he finds it delicious. Interestingly enough, according to the Otoko series, Kamina also enjoys her food.
- In episode 11, Simon gives Nia an emerald like gem he found while digging out of the Beastmen's prison. This mineral is believed to be the same one held in Nia's wedding ring.
- In the ADV dub, Nia was originally going to be voiced by Luci Christian.