Arin Kannazuki is one of the main characters from the Trinity Seven anime and manga.
Arin is the Trinity Seven of the Ira archive and a user of Chaotic Rune magic, whose appearance is strikingly similar to Arata's childhood friend Hijiri. Furthermore, she is also the Magic King's partner, becoming an early ally and later close friend to Arata.
In the AWA fics, Arin is a student at the AWA Academy and is part of Class 3.
In the XP4 fics, Arin debuted in the XP4 Heroes Coalition - Mission Chronicles.
Arin is a petite, slender young woman with short light blue-gray hair and a single horn. Notably, she also bears a striking resemblance to Hijiri Kasuga. However, Arin normally has an emotionless expression, rarely changing her expressions. Although, since meeting with Arata, she has begun to show a wider range of emotions. Her usual outfit consists of her school uniform, a white collared dress shirt worn with a dark blazer jacket with the school emblem, and a plaid mini-skirt. She also sports a plaid cravat bowtie, black knee-length socks, and loafers. On her left ring finger, she wears a simple band ring with rune inscriptions that are seen when activating her magic.
Magus Mode: In her magus mode, Arin switches to a dark one piece mini dress under a long sleeved hooded robe with white lace trims and tied with a thin red ribbon in a cravat knot. Her socks and shoes remain the same.
Arin is quite blase, typically only having a serious or blank expression and rarely showing any other emotions. Because of this, many of her actions and expressions usually do not match. Furthermore, Arin has often been shown to be blunt and lack common sense, generally never reacting the same way most people do in many situations. For example, Arin on one occasion chose to bath in the male bathroom because she preferred the quiet. Even when Arata discovered her naked by chance, she barely showed any reactions and acted nonchalant despite his presence. Often times, others have to correct and chide her for her behavior, which she usually finds difficult. However, despite her lack of expression, Arin is not quite a cold as she appears to be. In actuality, she can be kind and caring, even if she does not show that often. Arin gets along very well with her friends, caring for their safety and willing to fight for them. She has also been shown to be perceptive, once immediately noticing Mira's change of attitude towards Arata.
Notably, prior to meeting her partner, Arin has been noted to avoid interacting with others in favor of focusing solely on her research. However, since then, others have observed that she is more expressive and social towards those around her. In particular, she has become very devoted towards Arata, supporting and protecting him whenever possible. Arin can also act jealous when he interacts with other girls; although, she does not mind him being with the Trinity Seven.
Arin is a member of the Heroes Coalitions and is part of Team Kasuga. She also attends the Vanguard Academy as a student.
XP4 Heroes Coalition - Mission Chronicles
In Chapter 17, Arin is present when the Emotionless made an attack at the Royal Biblia Academy and with the arrival of the Of Guns and Magic team, they worked together to defeat the creatures. After that, Arin and the others thanked the team for their assistance and was later shock when the headmaster of the academy revealed that he has knowledge about the Heroes Coalitions.
XP4 Heroes Coalition - Neo-City Diaries
In Chapter 65, Arin alongside her team are being shown around at the Vanguard Academy by Lina Inverse and Merlin.
In Chapter 66, Arin is present during Vegeta's serenade in the school grounds of the Vanguard Academy.
Priestess of Yggdrasil - Both Arin and Hijiri are special entity, the Last Key. Their existence is needed to be able to reach the core of True Demon King, thrown away into the furthest end of dimensions. It is because of this ability Arin and Hijiri are able to reach Arata who is sealed by Anastasia in the Terminus Library.
Arin's Thema is Ruina from the Ira Archive, and her branch of magic is Chaotic Rune, which is based on the ancient writing style Norse runes. Specifically, Chaotic Rune manifests the power of gods into runes, capable of overpowering Magic King magic once enhanced. Using macros recorded in her grimoire Laguna Yggdrasil, she is able to perform a wide variety of spells both offensively and defensively by drawing symbols with her finger. Additionally, her magic is also considered to be one of the more destructive ones out of the Trinity Seven. In one instance, she was able to forcefully remove the Astil Manuscript's restriction on Arata, causing his power to become unstable.
Upon receiving the Demon Spear Gae Bolg due to her desire to protect Arata, Arin's magic abilities increased even further, even once breaking down time and space to teleport herself. Her offensive abilities, in particular, also further improved, able to outclass melee-types now despite once being only spell oriented.
Chaotic Rune has also been shown to be very compatible with Yui's Arc Symphony. By combining her spells with Yui, her magic is greatly enhanced, to the point of stopping a Magic King Candidates attacks. Furthermore, upon transforming Gae Bolg to God's King Spear Gungir, she can achieve another third of the Trinity. With Yui's Arc Symphony supporting her magic, she gains the Thema Victoria allowing her to complete the Trinity. At this stage, she has a very staggering amount of magic that becomes difficult for her to control.
During battles, Arin usually remains very composed, able to calmly and intelligently fight against her opponent. On rare occasions, she can lose her focus in dangerous situations involving her friends, especially Arata.
Arin is also capable of creating a Breakdown Phenomenon with the same destructive force as Arata's after her magic clashes with Hijiri's. Afterwards, she can access the Breakdown Phenomenon's world where she can locate individuals through their magic
- Tiwaz - An offensive spell that shoots magic energy that are capable of destroying a boulder. This rune can also stabilize the utilization of magic powers, as well as enhance other spells.
- Sowelu - A light spell.
- Eihwaz - A defensive spell that is able to ward off shadows and block physical attacks. This spell can be placed on other individuals, as well as summon a bow.
- Kano - A flame spell
- Uruz - Temporarily augments Arin's magical power to Yui's cardinal class level. However, there is also a risk her degrading into a monster if she runs out of magical power.
- Fehu - Summons an arrow of light.
- Othala - Returns a target to it's "homeland".
- Raidho - Manipulates the magic within a Magus' clothes around Arin to transform into different pieces of clothings of her choosing. However, after a certain duration, the spell loses effect which results in the clothes dissipating.
- Secret Art of Mistilteinn - Using Gae Bolg, Arin performs a strike that creates a powerful magical blast capable of even destroying Hijiri's strongest defense, Baldr's Blessing.
- Limit Release - Transforms Gae Bolg to Gungnir
- Valfodr Inferior - Upon achieving the Trinity by wielding Gungir and gaining the Thema Victoria with the support of Yui's Arc Symphony, Arin inserts all of her magic into Gungir and throws the spear to explode after contact. Even withholding the power was enough to render anyone unconscious.
- Perfect Guard - One of Gae Bolg's Armed Skills, the spear is able to consciously protect a target, allowing Arin to move at speeds rivaling even Lugh's.
- Hymn & Holy Seal - By enhancing Chaotic Rune Holy Seal with Arc Symphony Divine Song macro, Arin and Yui are able to create a barrier capable of destroying Arata's Meteo Dragonar
- Hagalaz - Together with Hijiri, creates a large rune on an object before breaking the same object.
- Laguna Yggdrasil - Having the appearance of a book, Laguna Yggdrasil contains all of Arin's macros which she can activate her magic spells. Normally, Arin usually has her grimoire change to the appearance of the ring she wears on her left hand. Notably, inside Laguna is the World Tree Library, a divine place created by Scathach that stores all knowledge of runes and supposedly vanished in the Ragnarok. Arin was able to access the Library by pouring her Ruina magic into Laguna and gain possession of Gae Bulg.
- Death Spear Gae Bulg - Due to her desire to protect Arata, Arin traveled to the World Tree Library where she received the Magic Spear Gae Bulg, which originally belonged to Scathach, the founder of Chaotic Rune magic. Upon forming a pact, the wielder is granted enhanced magical power, as well as the physical abilities on the same level as a martial arts expert. As such, even ordinary mages can become masters simply by possessing Gae Bulg. However, if the owner breaks the pact, a curse is invoked that will destroy it's master's heart. This spear also has the ability to nullify magic from the Ira archive and even allow her to break time and space on one occasion. As such, Gae Bulg is said to be so powerful it can pierce any defense. Additionally, the spear is a cornerstone for Arin's Partum Thema, allowing her to achieve the Trinity.
- God King Spear Gungir - Upon invoking Limit Release, Gae Bolg will transform to Odin's Armament, God King's Spear Gungir, an anti Magic King Weapon. In this form, Arin's magic power is further significantly increased. Additionally, Gungir allows her to complete another third of the Trinity.
- Arin's Demon Spear Gae Bolg is a reference the Irish mythical weapon of the same name. The founder of Chaotic Rune, Scathach, also shares the same name of the Irish woman warrior who gave Gae Bolg to the hero Cuchulain.
- Gae Bolg's second from Odin's Armament, God King's Spear Gungir is a reference to the Norse mythological weapon of the same name wielded by Odin. Odin, known as the god of Death and All-father of the gods, is also old Norse for the "Furious One", which is a reflection of Arin's Archive Ira, or Wrath.
- In the initial print of chapter zero, Arin's hair is colored brown in the color spread. However, in volume 1, her hair color has since been changed to her current color, light blue.
- In the first anime commercial, her bust size is stated to be 83 cm. However, in both episode one and chapter one, she tells Arata her bust size is 82 cm.
- The anime promotional material puts both Arin's and Yui's bust size at D, even though Arin's manga appearance is much more modest. Arata himself has compared their drastic size difference when both of them slept naked next to him.