Kasugaya Shizuri Castiella (
She has fair complexion, long white hair, and blue eyes. Two white horns protrude from her head, though they are usually hidden with a wimple. She is often seen wearing the College of Magical Arts' uniform, consisting a white shirt with a black tie and purple skirt.
She is described as being brave and has good leadership skills.
The Mirage Paladin
Kasugaya would first appear on the sand beaches of Onrai Island at night, and would encounter Kojou pass out on the sand. Kasugaya already knew of his name and kojou would have amnesia, with the only thing he remembers is his name. Kasugaya would talk about kojou being the the fourth primogenitor as she states, "you are the fourth of the original vampires, which should not exist. You are immortal and immutable. You have no blood brethren, order is not among your desires, and you are served by twelve beast vassals that are destruction incarnate. You drink people's blood, thereby slaughtering and destroying them. You are a cold, heartless monster astray from all doctrines of the world-that is what you are, Kojou Akatsuki." This statement by kasugaya would cause no reaction from kojou. Kojou would inquire of there whereabouts and her name which he response caused kasugaya to unsheathed her glowing vermilion sword and point its tip against kojou's neck and her words were "I am your watcher."
Kasugaya was on a training mission were her teammates Yuno and Rui, were they are required to take down Ms. Magatoki type fourteen armored Shikigami. They would discussed their plan over their radios in preparations to attack while observing its movements of the shikigami . Kasugaya would leave the first attack to Yuno, at the same time a new voice would appear, which would be the voice of Kojou asking what was his task over the radio, Kasugaya would remember kojou was apart of her team. The reasoning being kojou could not access his fourth primogenitor powers, had zero defense, no weapons or protective equipment, an amateur on the field of battle or a civil who'd wandered into the fray. Kasugaya would assigned kojou to support, by saying "please politely stand there, and do not get in the way," this comment would make kojou conflicted. kasugaya would face the shikigami by running straight head to take Yuno place while wielding a silver mace and swung her mace down towards the head of the Shinigami, this would caused an explosion, breaking the armor. As she began to touch up her disheveled clothes, sliver dolls emerged before kasugaya this would caused them to be on the defensives with kasugaya wield her vermilion blade. she would draw the doll away from the group, but Kojou would sprint in front of everyone releasing his demonic energy, which caused everyone and the air around to shudder by the oppressive power. Kojou would attempt to release his fifth beast vassal Regulus Aurum, but would disappear so after which left kojou open for an attack, the attack broke his bones causing him to pass out, Kasugaya would run towards kojou roaring from anger and hatred as her eyes were dyed crimson.
kasugaya would stay by kojou side as he rested in the hospital room, she would blame herself for letting kojou die, but would reassure her that it was not. Kojou would get out of the hospital bed stretching his back and pulling the blanket off, not knowing he was naked underneath would expose his parts to Kasugaya and Yuno, which caused both to blush and as a result kasugaya would land a punch bare handed on his unguarded part.
Kasugaya would be assigned a mission to explore the carceri as homework from an incident that took place when a debris attack training structure eight the night before. Kasugaya and her squad would encounter many foes throughout the caves from debris to larva. They would find another squad led by president Okurayama and Nozomi, and both squads would rest at the OS base inside the carceri. Kasugaya would enter a fight against an unknown woman, which put her entire squad unconscious. Kojou would be impaled by an mirage yukina, leaving kasugaya wobbling and in disarray as she pick up Kojou parka. (More would be added at a later time)
The Broken Holy Spear
Kojou would meet with Kasugaya in order to talk about her joining a club, that was established by Asiga, the club being called the "Demon sanctuary Research Club" or "Dem-Club" for short. This club is to investigate and research the management of the Demon Sanctuary and the actual state of demons' lives. Kojou waited till kaugaya finished class in order to talk to her. Kasugaya was happy and surprise to see kojou there waiting for her, but her mood soured when she glace at Yukina who was behind Kojou. Both girls were on guard of each other, on the pretense on "self-defenses." As all three walked together in order to find a spot to talk about the club, since they can't discuss it in front of other people. Kojou suggested to go to the school cafeteria, but was unsure of if it was opened. Yukina would suggest Goetia coffee at the north entrance of the station, but kasugaya was displeased at the sight of the pair interaction and would suggest to go some place else stating that " I desire to go to a tea shop. I do not wish to drink anything as crude as coffee...!" Kojou would refute saying that she would glug coffee down all the time back at Onrai Island, this made Kasugaya reddened as she stated that "Th-that was because it was coffee Kojou poured for my sake, so I could not simply refuse it!" Yukina would open her month saying that "Senpai, you like the pancakes at Goetia, don't you? The one with cream and nuts." Kasugaya glared at the Yukina. In the end they settled for vending machines.
Kasugaya, Kojou and Yukina would go to the hospital when they heard that Yuno and Rui were injured while fighting with tentacles. Kasugaya would meet for the first time Kiriha the priestess of the six blades of the Bureau of Astrology. Upon meeting her kasugaya instinct told her that Kiriha was no ordinary person and was like a "Wild wolf encountering an unfamiliar human being." Kiriha immediately notices that Kasugaya was an ogre and would subconsciously conceal her horns under her hand. Kirhia would meet with Kasugaya privately in her room stating that she need her help in slaying a demon beast and that hauras was the weapon to defeat the demon beast, kasugaya would join Kiriha in slaying the demon beast. She would let out a sign stating that "Somehow, I have come to understand why Kojou and Yukina do not get along well with you," this statement would hurt Kiriha feelings.
They would go on to slay the demon beast along with the help of Kojou, Yukina, Renia, Yuiri, Shio, Asagi and Yaze. Kiriha would deliver the finishing move with the Bureau of Astrogeology secret weapon called "Flat".
Never-ending Night Banquet
Reunion of Vampire Princess
- Duel - Wielding
- Abnormal strength
- Abnormal durability
- Abnormal speed
- Abnormal agility
- Leadership skills
"This fang is the light rending our darkness. This breath is the flame that sweeps away evil. Thy name is that of the fire-eating snake. Born from the soul of a saint, thy blade is immutable." The chant for paladin of Gisella who wield the sword hauras.
- Kasugaya'd horns are sensory organs that detect auras and demonic energy, but at the same time, if there touch or rub it would cause a sexual stimulation.
- She took the family name Kasugaya from from the original owner of hauras, that being Shinako Kasugaya.
- She could not use the newer vending machines at the hospital, and would require help from Nagisa Akatsuki.
- She is the first "Permanent" blood companion of Kojou. Feferred from Vol 21 Twelve beasts and blood servants
- She has a fondness for tea and coffee, particularly because Kojou poured it for her back at Onrai Island.
- Her level of experience when it comes to love is compared to "the level of an elementary schooler", according to Kojou.
- In light novel 17, Kasugaya is not an official attack mage, since the age restrictions in the attack mage labor law requires that one needs to have graduated from middle school in order to get a license.
- Kasugaya was the one who taught Kojou how to read and write in English. This was shown when Natsuki suspected of Kojou of cheating on the English test, when in fact it was Kasugaya who taught him.
- Gisella is a minor branch of the Lothringian Orthodox Church, and it is known as a heretical faction.