Shinichiro was the eldest Sano sibling and a hero to all his younger siblings Mikey, Izana, and Emma. He was a charismatic and empathetic person, often putting differences aside to better the other person. He was a heavily respected person in the delinquent world of Japan as the founder of Black Dragon. He led Black Dragon with a humble heart and was treated with notable respect, while also being a big brother to all three of his siblings. Even though he was a weak fighter, he lead the Black Dragon with his immense charisma. Even years after his death, later generation members still hold him in high regard.
Alongside other gangs, he enjoyed working on motorcycles and often tinkered in his garages. The garage in which he worked in became a haven for his fellow gang members to relax in. His prized position was his motorcycle, which Mikey inherited. He died on August 14, 2003. Baji and Kazutora broke into Shinichiro's bike shop to steal Mikey a bike, but while doing so, Shinichiro caught Baji red-handed. Not knowing who Shinichiro was, Kazutora rushed to save Baji by hitting Shinichiro in the head with a wrench, killing him. He was 23.
Even after his demise, people continued to look up to him and celebrate him. Although he was already deceased before the events of the story, Shinichiro continues to have an influence on the motivations of several major characters.