When Shiori was little, a major gang assaulted her parents, who apparently had asked for protection and owed money in return, held Shiori as a hostage for her parents until they gave them what they owed to the gang. After several struggles, they fatally shot Shiori's father and her mother had to sell many belongings to pay that money as long as they released her daughter.

Shiori at an early age and hidden from her mother, began working as a spy for different gangs. At first, people made fun of her for being so young and getting into those places, but she proved to be made in another way, they began to fear her for her incredible way of infiltrating and her intelligence, her capacity for firearms was tenacious , the Japanese Mafia "kitsune" targeted her and decided to take her into their family once she reached adulthood.

Shiori is intelligent and serious on missions, but in general you will always see a kind, joking girl with great self-esteem. When she's interested in a guy, she tends to make hints constantly