Born to Kazuo and Akira Katayama in March of 1993, Akio was their first and only son. His sister, Emi, was born two years later. Emi is also a witch, having many abilityes that Akio does not. He spent his first seven years in Nagano, Japan. His father was a powerful wizard there, having worked his way up the food chain to become head of his department. Akio doesn't know much about his father's work before moving to America, as his family does not discuss it. As a child in Japan, Akio would play outside with the other children of the province, having not a care in the world. His first language was Japanese, though his mother, who was actually born in America, taught him English from a young age.

When Emi was learning English, he felt a bit abandoned and wouldn't come out of his room. As Akio had been the brain child of the family, and was always doted upon, he felt left out. Emi was very smart and was picking up English quicker than he did. Eventually, however, she started coming to him to learn and he felt important - thus bringing him out of his bad temper. Abruptly, however, at the age of seven, the family left their home. They traveled lightly, doing Side-Along Apparition for short distance, and using the Floo Network at trusted hosts' homes. Upon arriving in America, they moved around for a couple of years, his father always telling him that they were moving for better jobs. Yet, Akio heard his parents whispering one night about the men who were after them. He began teaching himself defensive spells to better protect his family. Once school started, he began studying even harder. He didn't want them to be hurt by the bad men.

During the summer when he was twelve, the family moved to Texas and he finally felt at home. He felt free, and like no one from Japan would ever find them there. In the back of his mind, he knew that living in a highly populated Asian area would be safer. However, he put on a happy face and was glad to be in a stable environment. Finally. He encountered disaster when he was flying his broomstick over a cornfield, practicing Quidditch and Quodpot maneuvers. He lost balance trying a difficult trick and fell. He landed on his side, slicing his hip open on a stick. He hadn't mastered many spells, and thus bled as he limped the whole way home. He has a star-shaped scar there now.

In school, he was a loner at first. He concentrated on studying, and didn't really pay much attention to other people. Eventually, however, he became close friends with Sibyl Ballantine. He had crushed on her from afar, but bottled those feelings up when they became friends. He didn't want to take advantage of their closeness, and feared losing her as a friend most of all. It had been too long since he had someone to confide in. When he was fourteen, he began taking interest in other languages. He knew Japanese and English, but wanted to learn more. He began spending his summers learning French, then Russian, then German. He has mastered those languages, and is currently working on Italien.

Slowly, he began making more friends and opening up. His wit and humor began to shine through, and he started to join organizations. He branched out magically as well, though was frustrated when he couldn't master all of the charms and spells he wished. He was particularly bad at Herbology and Divination. He believed Herbology's weakness had something to do with the accident he had had when flying over the cornfield. In Transfiguration, he just didn't like the idea of turning objects into other objects, or worse, animals. It didn't seem right.

The more time he spent at school and learning, the more thirsty for knowledge he became. He convinced his parents to allow he and his sister to take trips during the summers to different places, and to Quidditch matches in Europe. He loved learning, and his next goal is to go back to Japan and learn about his family there.