Kiryu grew up in a small home with his mother and sister, his father committed suicide when he was 6 months old. Kiryu's mother couldn't afford to keep up with two children and without a father was hard, so his mother sold herself out. When he was 13, Kiryu grew up in disgust of his mother and protected his sister from the truth as he often lashed out and fought other children at school who bullied them for their mother. When Kiryu was 17 and growing angry, he turned towards a more rebellious path such as getting into more fights and even stealing from his mother and sometimes students with who he went to school with, as this behavior worsened he was eventually kicked out of high school, which led to him being kicked out from his home by his own mother.

At age 18 Kiryu bought a small apartment in Kabukicho, Tokyo's red-light district. There he worked as a cook at a Vietnamese restaurant, until he was introduced to a loan shark and well-known Yakuza boss, Kuze Yagami. Kiryu looked up to Kuze as a father figure and continue to work for him as he would make his way to becoming a member of the Hirasawa Family, a subsidiary of the Kai Clan. Kiryu ran his own crew of enforcers to keep other yakuza out of Hirasawa family turf and also extorting Businesses. When gaining knowledge about a rival family, the Sangoku family, who was pushing drugs in Hirasawa's turf, Kiryu took it upon himself to strike back at the rival family to send a message. The message is, shooting up an entire cafe killing many members of the Sangoku family along with their family patriarch. This was the first and only person Kiryu has ever killed as it mentally drained him and sucked the soul out of him.

After the shootout with the Sangoku Family, it created a war with the Kai Clan and their rival from Osaka, the Ryuji Alliance. Kiryu lost the respect from his boss, so in order to gain the respect back, Kiryu severed his own finger and gave it to his boss as a sincere apology. After the shooting Kiryu became feared amongst other Yakuzas and earned the name "The Dragon Koi" which referred to Kiryu rising to the top of fame and glory at a young age, which led to Kiryu getting a tattoo of the Dragon Koi on his back.

When Kiryu was 25 he was promoted to the ranks as a Lieutenant in the Hirasawa Family, he was tasked to help bring peace between the Kai Clan and Ryuji Alliance after the shooting 4 years prior, it was a bloody war between to two with car bombings, murders, and even families falling apart amongst the chaos. The Ryuji Alliance agreed to a white peace and revert back to normal business, but on July 6th, 2011 the 7th Chairman of the Kai Clan was murdered by an unknown assailant, creating a massive power struggle within the Kai Clan. Kuze Yagami was appointed to become the 8th Chairman, until a dark rainy night in July, Kiryu was tipped off by a Tokyo PD Detectives that there was an assassination attempt on Kuze. When Kiryu made his way to Kuze's office he found him dead and then being surrounded by Tokyo Police officers, being arrested and sentenced to 10 years for murder.

Being Sentenced to prison, Kiryu suffered from mistreatment by guards such as being beaten and starved from food. Though Kiryu meant a former Yakuza in prison who taught him practices of Buddhism, learning a way to peace Kiryu became a buddhist and looked forward for a new future and chapter in his life.

Being released from prison, Kiryu was rejected by Japanese society for being an Ex-Yakuza. Kiryu moved to Los Santos starting a new life, becoming a member of the Del Perro Fishing Club which gave him a part-time position as a chef in Pearls. Kiryu also started a full time job as a mechanic at Auto Exotic as he dabbles in street racing with fellow Auto Exotic employees, though Kiryu is still discovering himself but also leans back into his criminal lifestyle.

"I need beer."