When Sakura decides to become a ninja, her dream is to be able to stand up for herself.
She's been bullied for as long as she can remember- bullied for her large forehead ("billboard brow"), for her pink hair and exotic green eyes, for her shy countenance. She can't remember a time in her life when there wasn't somebody trying to drag her self worth through the mud.
She isn't exactly sure when Inner comes into existence. It could have been when she tripped down the staircase and Ami was there to laugh at her all the way down. It could have been when she told her mother (not mom, not anymore) about wanting to become a ninja and instead of supporting her, instead of listening, she screamed and shouted and was furious.
"Harunos are not Ninjas!"
Inner is her, just as she is Inner. They are not separate entities, not really. Inner is the pieces of her that she cannot show, cannot allow to be seen because even though she tries (tries so so hard) she is scared and shy and vulnerable.
But Inner is her sarcasm, is her sly wit, her ruthless intelligence, her meager yet hard-won scraps of self-confidence. And everyday, even if it feels as if she is suffocating, as if she cannot breathe, as if people are taking bits and pieces of her to mold her in their image, she has a safe haven to be herself.
To Ami she is a quivering mess of a girl, somebody to hurl scathing insults at to assuage her own inferiority complex. To her mother she is a daughter who will uphold the Haruno name. To her father she is his dutiful little princess who will get whatever she wants except what she wants the most.
In the end she is all of these things- but she is also more- because Sakura wants to be a ninja above everything else and that means being strong and determined and ruthless.
So she approaches her parents this time, not just her mother, and firmly requests- no, demands- that they enroll her in the ninja academy.
They refuse.
And she knows, knows, that its not because they care about her. It's not because they don't want her to get hurt or because they're scared for her.
No, it's because it would ruin their reputation. It's because shinobi are disgusting murderers (but they're not because they saveprotecthelp people) and because they want her to be a demure civilian housewife (but god she's never wanted that).
So she threatens to go to the Hokage, because the academy is always looking for new recruits and she is willing to go over (or under or anywhere) to do it.
Her parents are smart enough to realize that allowing her to attend will be much less of a hassle than refusing her.
However, Sakura knows that this is a Pyrric victory at best. There will no longer be even the small comfort or support of people who think they know her. Because she is no longer a child, no longer something easily moldable or somebody to protect. She is something frightening, something different, something other.
So she returns to her room and falls asleep to raised voices. Her heart is torn in a confusing mixture of victory (pride) and sadness (regret). And if her cheeks are suspiciously wet, well, she left the window open for any stray raindrop to fall through during the night.