|Akiko is not intentionally uncouth - she just has never been taught any better. She can be generally spiteful, and basic manners to her are trivial and things to be discarded. Rather than face having to owe someone, she'd rather deal with whatever life throws at her alone. She can be very flirty and...aroused, especially around girls, and the first part of this is almost certainly a mother-inherited trait. By no means quiet, she'll throw an insult or two around willingly, or maybe even more. Her kettle of fish changes when someone might prove useful to her - she grades people on their usefulness rather than whatever else they might be. This causes her to be self-preserving, bitchy and judgemental, and not exactly someone you'd like to meet on the street. Genuinely uncouth, she lacks the general understanding of right and wrong both physically and mentally, which can lead her to make morally wrong or rash decisions.
History: Aika was a Firebender, and she considered herself very skilled in what she purely called 'the act of seduction.' Her actions seducing Kaito, a young Earthbender, led to her becoming impregnated with a child. The child was young Akiko, who would grow up fatherless due to Kaito's lack of manifestation later on (unsurprisingly.) Having miscarried twice with children, both from different fathers, Aika was used to desertion. So, understandably, she was happy when Akiko made it alive, as she was the first of the three to do so. Being fatherless didn't particularly affect the child too much, because she'd never had one and they always said you couldn't miss what you never had. Whilst Aika was never the best mother to Akiko, you had to give her credit for trying her best.
Akiko was independent almost from the get-go to say the least, except when entranced by her mother's firebending. As children with close relatives did, from a young age Akiko began to experiment to see whether she could too. She discovered - not too vividly, but it was definitely there - that she had the Firebender gene age five. Akiko still debates whether she's ever seen her mother prouder - she doesn't remember much about her life at age five, but the moment of discovery was always going to be a very vivid moment in both her mind, and her mother's. And not just because it resulted in a burnt out hollow of an ash tree and a need to replace the fence, not to mention the incinerated grasses. Aika had kind of hoped she'd get the Earthbender gene instead, the one she considered to be less destructive, but it was not so.
Aika couldn't train Akiko herself - she had watch her maturing child develop an Elektra Complex for a family friend who tutored her instead. This was purely because Aika believed herself to be too sporadic and overwhelming for a task that needed time and care. She made Akiko swear to never take this festering Elektra Complex anywhere, which Akiko herself was never intending to do, although she was beginning to display her mother's thrillseeking traits. Akiko was difficult, and hard to keep focused, she wanted to start trying everything right away to sate her need for adrenaline, and the training finally ceased when Akiko turned fifteen, by which time the Elektra Complex was at its peak, so Aika was more than happy to remove her daughter at this point.
Three months later, Aika had been up to her usual tricks, and Akiko came home to her passed out on the couch. A premature stillbirth, after finding out she was pregnant again, took her life and left Akiko, bridging on sixteen, parentless. Akiko saw nothing gluing her to where she had previously resided now, and left town in favour of what she saw as a freer lifestyle. Trying to be self-dependent within the country obviously wasn't working out too well after merely a few weeks. So she shunned the country to travel to Republic City, where as far as she was concerned the page was new...except for when she looks at those in authority, the lingering effects of the Elektra Complex make it a whole other board game.
(Note: The thing with the Elektra Complex is a daughter's possessive nature for other male figures of authority or importance in her life (romantically and sexually) in absence of her father, which is the original meaning :D )