BlaKatz
He was the treasurer of the infamous Akatsuki Gang. He has no interest in anything other than money. His violent tendencies and short temper make it hard for him to make good impressions, not that one is needed when you're in a gang.
She was a street rat, abandoned by her parents long ago. She grew up learning three things: steal, hide, and run. She has to steal in order to survive. After all, nobody wants a dirty, pink haired thief.
While running errands, Kakuzu sees Sakura successfully steal money and food. He even acknowlages how good she is at running and disappearing. It was a rare sight that he gave no other thought about...
Until he realised his wallet was missing.
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"I should kill you for stealing my wallet."
"You should kill yourself for being so ugly."
"Kakuzu, enough. The girl is a useful asset. She will stay with us and do jobs until she can pay off her debt. Do not harm her."
"You got off lucky, street rat."
"Yeah? Well you're still ugly, Stiches."