Family
Although Ryuji has lived a fairly priviledged life his family connections and rapport outside of the Yakuza leave much to be desired. His mother left when he was a child. He was raised by a man who was not his biological father. And, right before he died he found out he had a half sister. Ryuji thinks little of his "family" though he does not quite insist that blood doesn't matter. He was fairly annoyed with Goda Jin, the only father he'd had. It isn't until he faces mortality that he realizes he could have had a very nice family life. Unfortunately, his stubborn pride made him difficult to be around.In Dead Souls, we get to see a much more family oriented Ryuji as he is taken in by a Takoyaki Chef looking to pass down his art. Ryuji addresses this man as "Pops" and Pops in turn relies on Ryuji to learn quickly and well so that he can take over the shop. Truthfully, he has little real interaction with most of the people that could be considered his family.
Jung Suyeon: Mother
The wife of the head of the Jingweon, Korean Mafia, she and her son along with two others were spared when Fuma wiped out their clan. She lived with Goda Jin for awhile. She later left to go into hiding with Kawara Jiro. She marries Kawara and mothers his daughter Kaoru. She was killed by the Jingweon and her daughter was forced into hiding. She left her son with Goda Jin.
Goda Jin: Father
Goda Jin was the Fifth Chairman of the Omi Alliance, he raised Ryuji after he took in Suyeon on Fuma's request. When Suyeon left, he begged her to let him keep the child as he had no children. I feel that he wanted an heir, but, I also believe that he truly wanted to give Ryuji the best he could. I would even go so far as to say that Jin doted over Ryuji and this is what made him so proud and stubborn (and somewhat entitled).
By the time we actually meet him, he is old and sick. He wants nothing but peace between the Omi and Tojo. Unfortunately, Ryuji believes that his old man is weak. He believes that strength should rule. During the meeting with Kazuma and Daigo, Ryuji takes over the clan, kidnaps his father, and Daigo. He plans on restoring the clan. At no point, however, do Ryuji say that he wants his father dead. Nor does he make it a point to hurt him. When Kaoru and Ryuji are reunited, it is Jin who confirms the police detective's claims. In fact, Ryuji blamed his adopted father for his mother leaving him. Goda Jin insists that when Suyeon left he begged her to let him keep Ryuji. Ryuji accepts this as truth, but never tells his father as he doesn't have the chance too.
In truth, Ryuji was often compared to his father. He hated that. He hated being compared to his father becuase he was not given the benefit of the doubt - he felt he wasn't able to live up to his father or do anything that would be better than his father. Although, he admits that his father was a good dad to the hostess, Hina. Ryuji says that Jin was strict but when it came down to it his dad gave him everything he could have wanted. He mentions that he always got his way. Ryuji also believes that because he is living his own life (outside of the Omi and outside of his father's shadow) he will be able to surpass him one day. Despite everything that had happened, Ryuji doesn't seem regretful. He seems to more or less respect his father, though he doesn't outright say it.
Sayama Kaoru: Sister
Sayama Kaoru is best known as the Yakuza eater. She harbors a grudge against all Yakuza for the death of her mother. She blames Tojo Clan for the way her life ended up. She is actually Ryuji's half sister, they share a mother. She was raised by Sayama Tomiyo on behalf of Kawara Jiro. After some digging she learns that she has a brother, Ryuji. At the end of Yakuza 2 she insists that her only surviving family, Ryuji, and the man she loves, Kazuma, can't be fighting. Unfortunately, Ryuji and Kazuma have something to prove to each other. She is forced to watch them wail on each other. When the issue is resolved, Ryuji dies in her arms half wishing he could have been a better older brother. He was happy, if only for a moment, to have a cute younger sister.
Dead Souls features Sayano Kaori, a Kaoru look alike. Ryuji mistakes her for his sister and chases her into the Quarantine zone. After talking to her, he finds out that she is not his little sister but she is a little sister after all. Kaori is looking for her brother and relies heavily on Ryuji to find him. When the siblings are reunited, Kaori thanks him for being just like a real brother to her. Ryuji is taken aback as she leaves with a smile. He laments on the idea of being an older brother to Kaori for a short time when he hadn't even been that for his own sister. He then says, "Kaoru, where ever you are I hope you're happy."
Given the chance and time, he would do anything to support his sister. He would be initially awkward about it, true enough, but having someone to support and someone to support him really would have meant a lot to him. Unfortunately, even if he wanted to be there for Kaoru, he would probably try to keep his distance to prevent her from getting hurt. He would probably justify it as suiting him better to work from the shadows.
Pops: Takoyaki Mentor
After being expelled by the Omi Alliance, Ryuji was taken in by "Pops." He ran a Takoyaki stand and had almost resigned to the idea he would never find a successor. After he took in Ryuji he started training him in the way of the Takoyaki Chef. He looks at Ryuji as a hard worker and wants him to absorb everything he can. In one particular instance he needs to kill an octopus. He tells Ryuji that one must aim for the vitals. Be quick and efficient so that the creature does not suffer. He states that one must do the job with love. He then insists that if one can do that, they are a true Takoyaki master. At that point he addresses Ryuji as "son".
When the Quarantine starts to take over Kamurocho, Pops goes missing. Nikaido kidnaps Pops and turns him into a zombie to teach Ryuji a lesson. He does this in order to cut all ties with the useless life that he thinks Ryuji has. Pops is the final boss for Ryuji's third chapter. He morphs into a large octopus zombie in Asia. Despite Ryuji's best efforts he cannot kill Pops. He flashes back to the lecture with the octopus. As he aims for the spot right between the eyes, Ryuji says "Forgive me".
At that point, Pops was the only family had left. Ryuji was content to clean up after Nikaido and simply stop him. After he has to kill Pops, Ryuji's attitude changes. He feels there is little point in talking. He is going to give Nikaido a does of medicine (see gatling gun). When he kills Pops shows the only time Ryuji regrets the things he'd done or been involved in. For a moment he believes that if not for him, Pops wouldn't have been involved. However, he also knows he can't change that so he resolves to stop Nikaido.
By the time Dead Souls takes place (even if a spin off), Ryuji has had five years to mature. He respects family and the bonds of family a lot more. He shows little moments of pain and nostalgia as though he wishes he could do more. Often times, he is not afforded that.