Taiju enjoys tormenting Takemichi Hanagaki, the main protagonist of Tokyo Revengers, and has absolute control over the Black Dragon Gang. He is 16 years old in the 2005 timeline that Takemichi frequently goes back to in order to change the future.
Before becoming the leader of the Black Dragon Gang, Taiju was a member of the Tokyo Manji Gang. He was born into a line of criminals that had been entangled with the Black Dragon Gang for generations. He was the oldest brother of Hakkai and was always looking out for him.
At some point, Taiju was accepted into the leadership of the Black Dragon Gang and took over from his father. As the leader, he was able to completely reforming the gang and make it more efficient. He was also able to keep the gang in check and prevent them from doing too much damage.
Under his leadership, the gang began to make allies with other gangs and Taiju was able to keep them from going to war with each other. This allowed the gang to gain more power and influence.
Taiju was a mysterious character in Tokyo Revengers and his age is finally revealed in Chapter 81. He is 16 years old and is the older brother of Hakkai, Toman’s Second Division Captain. He is a formidable leader of the Black Dragon Gang and is a force to be reckoned with.