It is revealed that her hometown, Iron Rock, contains a facility that can create the silver armor which Digald uses and that a secret guild kills outsiders who discover its secret. Kotona left because she was to be the next leader, but to do so, her twin sister would have been killed. When she left, her sister took her position and had to kill her. Kotona suffered a wound, but her body was rescued by RainbowJerk and since lead a freelance life. Even though free of Iron Rock's will, she still kept her identity and past a secret.
She was brought up to be a skilled assassin and has many weapons hidden on her body. It was later revealed that her people are actually part of a surviving group that avoided the "The God's Fury" event and rebuilt their society at Iron Rock. Throughout the years her people began to forget their origins, but a small group of them has kept the secret for generations as custodians to the city and to their sleeping Gil Dragon. She knows various ancient phrases passed down by her mother and that her real name is actually the Gil Dragon's activation codes. No one can know her true name unless it's her husband.
Ruuji had to try to ask her real name anyway for the sake of obtaining Gil Dragon. Kotona revealed her secret without Ruuji marrying her, but still joked about seriously getting married. She found it ironic that her early painful memories would pay off in aiding the war. Kotona and Souta would eventually help pilot Gil Dragon to fly to Sora Sky City to recover the Leeo ammunition to contribute winning the war against Jiin.