Myself in Naruto Style

In the middle her young appearance,

Left her Shippuden and right her chunin appereance.

Her story would be like this (in short)

On a night all the villagers of her village were killed when she was about the age of 6. One of the assassins and leader of the group kept her alive saying she has some kind of weird chakra. She was later found by a chunin of the Konoha Village and kept there for a while. But she didnt had any memory.

Later she was reunited by that man and trained, but when she learned he killed the chunin that took care of her in Konoha, she runned away.

She then out of sorrow started killing people and was called "the Killer without Emotion" Due that she kills her victims without any emotion.

When she was at Konoha she met Naruto and they became good friends, but due to a hit on his head, Naruto doesnt recognize her.

She appears later when helping Naruto.

Her original name is Chojoko but she changed it to Natsuko after running away.

Her last name is Kuroda.

Natsuko has two kind of chakra's, it seems that some kind of person or spirit is always close to her and it can be used to defend and attack. She calls the spirit Tomo, coming from Tomodachi=Friendship.

Tomo actually is Natsuko's other half due that she has a split personality.  Tomo is all her sadness and hatred, what was so strong at some point it created a invisible creature.

Tomo can only be seen by people that can see chakra or when Natsuko powers up.

Also due to Tomo everybody that gets close to Natsuko will get hurt and leaves. So she ends up alone, thats why she is first acted cold against the Konoha villagers.

A reason for this misfortune could be because Tomo is simply jealous. 

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So thats a short information about her XD

I shall expand and colour her her maybe another time 

If you are interested in her story please ask and i will tell with all the details.