Summary

Aislin was born in Ballyieragh, Ireland to Akio Okano and Cáit Connelly, in a family of Magi not well known in Japan, but popular in Ireland. Aislin and Ailín, her younger brother, were taught ever since they were children in magic, and Akio taught them how to emply their magic in practical skills such as swordsmanship and martial arts, and as such they are proficient in both arts. During her childhood, Akio also started to infuse the Magic Crest in Aislin, as she would be his successor, creating friction between Aislin and Ailín. The boy eventually gave up after seeing how painful it would be, and that it dragged Aislin to the Holy Grail War.

Until she was 6 years old, Aislin and her family lived in Ireland, as she and her mother were happier there, rather than in Japan, making Akio travel to Japan a few times to check on everything. However, that not only put a dent on their finances but also didn't allow her to properly focus on her studies, and eventually moved to Japan, where she was given a stricter and more rigorous training schedule. During her time in Ireland, she befriended Neila Donaghue, a fellow Magus and heiress to the Donaghue family, and they became close.

When Aislin was seven years old, and her brother three, she got involved into an accident with an arrow, as while Akio was practicing archery, Ailín crossed the path of the arrow, making Aislin push him out of the way and the arrow buried itself on her left shoulder, leaving her with a scar, but not in life danger. On that same year, her father took another boy of her age as another student, named Kei Saito, from a relatively new lineage of Magi.

Since Kei had the same element alignment as Akio, fire, the Okano children weren't pleased and began a rivalry with Kei for Akio's attention and approval, despite that the Saito family was welcomed quickly into the family and spent some summers with the Okano family. When she was 10 years old, during the summer, Aislin and Kei were fooling around, trying to prove whom was better, and Kei decided to try how far he could take his magic, despite Aislin's worried protests because of her brother being there. Kei ignored her, and lost control of the fire magic and the mana output, setting the stall on fire.

They escape relatively unharmed, as their fathers quickly rescued them, but it burnt the stall and everything inside, and scarred the kids. Kei started to fear his own power, and Aislin blamed him for being stubborn and not even apologizing, and ever since then they can't stand each other.

Around her 13 years old, a boy from a different class had a crush on her and approached her, talking a lot with her. She was initially curious about the "crush" he was talking about, and decided to give him a chance, but Isamu turned out to be too clingy and she became bored and uncomfortable with him. Besides that, in her opinion it was too early for her to date someone, and as such she broke up with him, but he keeps trying to make her fall in love with him. Despite her attempts to avoid him, they study in the same school making it nearly impossible.