Kannazuki, Arin

神無月アリン

A mysterious girl who claims Arata to be her husband. She resembles Hijiri, Arata's cousin and childhood friend. Arin rarely displays emotion and cares little for others' opinions of her. Her first encounter with Arata happened while she was bathing in the men's bath, preferring the quiet (very few men attend the academy because females are usually more attuned to magic). Despite being discovered by Arata, she acts casual as if nothing had happened. Although she shows little emotion herself, she is quick to notice it in others. Arin has no memory before the age of 8; she recalls a void of nothingness, slowly becoming aware of the world around her, she began to cry, then started wandering and was eventually discovered by the headmaster who took her to the school, where she has remained ever since.
Arin believes herself to be the magic king/demon lord's wife, although no official marriage has been arranged, thus she becomes quite jealous of anyone flirting with Arata; however, she has stated that she doesn't mind the Trinity Seven because they are all friends. As time progresses, Arin starts to show a little more emotion, such as smiling and blushing when speaking to Arata, and the other Trinity Seven members have commented on this, saying that they prefer this side of her.
Arin's Magic is mostly spell-based. Her branch is chaotic rune, which is said to manifest the power of the gods; her magic is capable of overpowering the magic king/demon lord Canadit's power once enhanced, and is activated by writing Norse runes in the air. Her magic is highly compatible with Yui's Arc Symphony.