Nanao Tepes/Synopsis

Volume 4
Nanao Tepes is first introduced in Volume 4 as a boy, under the alias of "Nanao Sasaki". Though one of Arthur's and Lancelot's classmates, he had been unable to participate in the Gym due to his weak physical body and was paired with Arthur as his gym partner due to his previous partner Nico Rasalgethi having to suddenly leave. He is part of the student council and is working on the committee for the school festival.

When Arthur has a disagreement with one of the older students working on the festival committee over the specialty fireworks the latter had ordered leaves him in a bad spot Nanao uses his vampyric powers to take over his mind and has his work quietly without causing any more trouble from now on.

Unfortunately, this comes back to bite the young dhampyr when this same student is brainwashed into attacking Arthur during the sports festival and in the process is made a suspect in the investigation into who had been attacking Arthur lately. When the two comes to blows for a short period of time when they learn each other's secret heritage the fighting between them is ultimately ended when Arthur renders Nanao unconscious.

Later on, the two friends manage to reconcile their differences with minimal difficulty once Nanao's innocence is revealed and Arthur reveals that he's not part of the hero tribe anymore.

Volume 10
Nanao, Tomoe and Sköll faced off against Misteeta Sabnock and Ladora Buné during the Rating Game between their masters. When Tomoe's ability to use Sakuya and Durandal and Sköll's Lycanthrope ability were sealed, Nanao sacrificed her to buy time and allow the curse to deactivate so Tomoe can defeat them. Back at school, the Occult Research Club decorated their club room into a haunted house for the school festival where she dressed as a female Dracula which all the girls found adorable. She and the rest of the Occult Research Club members were later seen peeping at Arthur who confessed his love to Mina, congratulating Arthur who successfully became Mina's boyfriend.

Volume 11
In Volume 11, Nanao, with Kaoru and Annabelle, goes to the Grigori headquarters to increase his powers

Volume 12
She returns in Volume 12, disappointed that she gained nothing until she heard about Arthur's death from Georg Faust, causing Nanao to undergo a change where he can create an enormous amount of darkness that devours everything (even the mist created by Paradise Lost), which allowed her to defeat the latter.

Volume 16
In Volume 16, Nanao returns to her birthplace to meet up with Satanael and Alice Evangelista who were confined in the Tepes Castle. She was then reunited with her older sister, Valerie, who became the new "King" of the Tepes Clan, but was greatly saddened to see her mentally broken due to overusing the Longinus, Twilight Graal, caused by her older half-brother Dimitri Tepes. After a tea party with Valerie, Dimitri appeared and agreed to Nanao's request to "free" Valerie. Nanao later learned the truth to her older brother's true purpose and becomes determined to save Valerie. Upon reaching the lowest level of the basement, Nanao was shocked and despaired to see Dimitri having extracted the Longinus from Valerie as she shares one last conversation before Valerie's "death". Angered and disgusted by Dimitri and the Vampyres that made use of her sister, Nanao's hidden power awakens as she killed Dimitri and the Vampyres that supported him. When the mass-produced Evil Dragons start attacking, Nanao used her darkness to cover the entire town, devouring the mass-produced Evil Dragons before going to assist Arthur who was fighting Euclid Lucifuge. Nanao then attempted to attack Drakon who gives out a retreat order but to no avail due to Drakon's ability. After Drakon and his team left, Nanao carried Valerie with her and had one last conversation with her father and eldest brother Vladmir. After their return from Romania, Nanao participated in the meeting formation of Eden.