Nanami values strength and power, and is a child prodigy at Vanguard. She looks up to her boss, Esuka Hibino, and aspires to defeat her at a cardfight someday.  Initially, she refused to do anything that she would deem pointless until Shinemon changed her way of thinking and began to adopt his belief that never giving up, no matter how pointless it seems, is worth it if it could mean an opportunity to change everything. 

(Source: Cardfight!! Vanguard Wiki)

This is the story of "Shinemon Nitta", the future manager of Card Capital.
 
10 years before the reunion of Aichi Sendou and Toshiki Kai, the card shop run by the Tokura family "Card Capital" was going out of business. Then came the attempt to take over the store by Esuka Hibino, the owner of a major card shop.
 
In order to protect Card Capital, Shinemon Nitta stands up as the "Self-proclaimed Manager!"
 
(Source: Cardfight!! Vanguard Wiki)

Nanami Gonomi