Koga Akira is 21 years old and is the eldest child of the Koga family. He has a younger sister named Koga Rei. Akira's family is an Alestian branch of the infamous Crane Clan of Masayume.

Akira was Cassie's first “love”. She met him a few years ago through Arashikage Kanae, who was giving him lessons in calligraphy when Cassie began her Masayuman language lessons. Cassie and Akira's relationship was on pretty hard until last year, when his parents were finally able to secure the arranged marriage they had been working on for the past several years.

He is now married to Koga Mio (formerly Suzuki Mio), of the Unicorn Clan. And while Cassie and Akira's relationship ended due to his sudden marriage, a sense of loss still lingers for both of them. Either way, their relationship has been kept secret to this day, although Arashikage Kanae is in the know (mostly due to her own shrewdness) and Rei has had her suspicions.