Yuri was born and raised in the Lower Quarter of the Capital. As an orphan, the local residents cared for him as if he were one of their own. He became Flynn Scifo's friend when Flynn moved to the Lower Quarter. The two would practice sword fighting and compete with one another, where Flynn always won. They vowed they would fight to make people happy. When an accident occurred in the Capital, Flynn's father died protecting the citizens of the Lower Quarter. This event caused Flynn and Yuri to strive for different perspectives in life. After the two reached adulthood, Flynn joined the Imperial Knights in order to change the Empire from within, while Yuri remained in the Lower Quarter. When Hanks told Yuri to "work properly", Yuri reluctantly joined the Knights, as well, but he nearly failed the recruitment exam by saving a fellow soldier from being killed by a monster. Because Yuri managed to kill the monster in one blow, his instructor decided to allow him in the Knights.
As shown in the movie prequel Tales of Vesperia: The First Strike, a major part in his time in the imperial knights is with the Niren Corps often arguing with Flynn, Hisca Aiheap, and his captain, Niren Fedrock, though he admires Niren's ideals. His personality during the movie is much more impulsive often doing things on his own but holds ideals in the highest regard. After returning from a mission to destroy a large pack of monsters from attacking a town due to the increase of aer, Yuri starts a bar fight with a local guild though gains the respect of the guild leader. After Niren and Chastel Aiheap go to investigate the aer and Flynn to attend a gathering in his place, Yuri and Hisca help to quell another monster attack. During the attack, Niren's dog, Lambert, is taken control of by a monster comprised of pure aer forcing Yuri to kill him.
Disheartened, Yuri decides to take care of Repede, Lambert's son, and clashes with Flynn who failed to acquire reinforcements. Niren decides he must take matters into his own hands as Yuri, Flynn and the rest of the Niren Corps go to investigate a fortress which is the center of all of the aer. Yuri, more than ever, tries to save everyone but after successfully stopping the device causing the overflow of aer, the fortress collapses and Yuri fails to save Niren who was caught in a sinking sinkhole. Flynn informs him that Garista Luodur was probably involved in the device as they confront him. When he reveals his plans, he attacks Yuri and Flynn. Yuri, using the blastia that Niren gave to him before he died, catches Garista off guard and kills him. In the aftermath of this, Yuri, who is seen in his familiar black clothes from the game, leaves the knights with Repede, who now has Niren's pipe. The experiences Yuri had in the movie carry on with him throughout the story.
For the story's first part, Yuri and his party chase the core thief across the world. After discovering that the thief in question, Dedecci, is linked to a much bigger operation by the Blood Alliance leader Barbos, one of the Five Master Guilds, and the imperial councilman and Capua Nor magistrate, Ragou, Yuri's group puts all of their efforts into foiling their scheme to control both the empire and the guilds. Along the way, they discover the horrors that Ragou has committed against his own people, which include taxing them to impoverishing levels, kidnapping and killing citizens and children, and disposing of the corpses either by feeding them to monsters or selling them for money. Following the defeat of Barbos, Ragou uses his standing in the council to reduce his charges. Unable to forgive Ragou, and knowing that the laws of the empire will never punish him, Yuri takes matters into his own hands and murders him, a secret that he keeps from the rest of the party for much of the game. Following this, Yuri marks his departure from the laws of the empire by announcing to Flynn that he will start a guild, and with Karol Capel and Judith at his side they form Brave Vesperia, named after the brightest star in the night sky by Estelle.
During the story's second part, Yuri and his party clash with Cumore, a captain of the imperial knights who has ambitions of becoming the Commandant. Cumore's crimes are soon revealed to be just as bad as Ragou's, and include forcing people to work in slave labor camps and sending innocent citizens, and even his own soldiers, on a suicidal mission into the desert to search for Phaeroh. While the party hopes that Flynn will be able to bring Cumore's actions to an end, Raven off-handedly comments that the only cure for the stupidity for people such as Cumore is death. This unintentionally inspires Yuri to strike again, chasing Cumore out to the edge of the town, where Cumore falls into a sandpit.
Cumore begs Yuri for help, but his pleas fall on deaf ears and he slowly sinks to his death. However, the event is witnessed by Flynn, and the two become engaged in a heated argument. Flynn insists that Yuri's ways are wrong, telling him that his behavior is that "of a common criminal", while Yuri defends himself, stating that his actions were necessary. At this point, Yuri has rejected the law entirely, stating that it is nothing more than "the tools of whoever happens to hold all the chips", and leaves Flynn with the haunting message that he understands his actions entirely, and has chosen to dirty his hands in order to destroy the villains of the world. When Yuri afterward realizes that Estelle was listening to everything, he asks her if she is afraid of him. While she knows that what he has done is against the law, Estelle says that she understands Yuri's reason and thinking, since his actions have saved the lives of others who would have been victimized by Ragou and Cumore in the future and also states that if she ever was to be taken down by him, she knows he would have his reasons, as well.
Yuri's sins are eventually revealed to the party at Nordopolica, following the death of Belius by Flynn. When Flynn crosses paths with the party, insisting that they hand over Estelle and the Entelexeia's apatheia, Yuri tells his friend that he is going down the same path as Ragou and Cumore, and that if he does not stop, he will have no choice but to dispatch him as well. Karol is the most affected by this discovery.
Following the revelation that Alexei Dinoia has been the mastermind behind Ragou, Cumore, and even Barbos, and the kidnapping of Estelle and abuse of her power as a Child of the Full Moon, Yuri begins to realize that his actions have solved nothing, and that all they have done is make way for a monster even more twisted than either of his two victims. Resolved to put an end to Estelle's suffering, Yuri decides that his already dirtied hands are the only ones that have the strength to free her. However, he is stopped by his friends, who insist that Yuri's attempt to bear the burden of defeating the monsters of the world all by himself will only hurt him, and them, in the long run. Inspired by their dedication to him, Yuri agrees to travel with them to stop Estelle, only to find her under the complete control of Alexei by the time they reach Zaphias, who brings forth the Enduring Shrine of Zaude. Realizing that there may be no other way, Yuri prepares himself for the worst case scenario: his original plan of killing Estelle. However, his words eventually manage to bring Estelle out of her power-fueled trance and restore her to her normal self.
With Estelle back in the group, Yuri and his friends travel to Zaude and stop Alexei. After defeating Yeager, they confront the Commandant and they fight to stop him. However, their efforts are in vain, and Alexei activates Zaude. To everyone's surprise, Zaude was actually a barrier blastia that prevented the Adephagos from destroying the world. After Alexei's death, Yuri is stabbed by Flynn's subordinate, Sodia, and he falls to the ocean below.
Yuri then wakes up in Zaphias, and he discovers that he was saved by Duke, who takes Dein Nomos back. Reuniting with Estelle and Repede, Yuri learns that everyone was searching for him after his disappearance. After getting the group back together, they help Rita and Estelle in converting the apatheia of the Entelexeia into spirits that can stop the Adephagos. However, they learn from Sylph that Duke has lost his faith in humanity, and has decided to sacrifice everyone's lives, including his own, to use the Tarqaron and destroy the Adephagos. Realizing that they will need all of the blastia in the world to be converted into spirits, Yuri and the group call all of the world leaders and ask for their permission to go through with their plan, which is approved. During this time, Yuri confronts Sodia about her actions and fights Flynn to resolve their differences once and for all.
Arriving on the Tarqaron, the party is confronted for the final time by Zagi, an assassin who has been obsessed with fighting Yuri. Defeating him for the final time, Yuri slashes at him and causes him to fall to his death. At the top of Tarqaron, the party fights Duke to stop him from sacrificing humanity. Emerging victorious, they try to stop the Adephagos but discover that they do not have enough power. To Yuri's surprise, Duke aids them by lending Dein Nomos and they successfully stop the Adephagos. Afterward, Yuri continues his journeys with his friends.
Project X Zone
Yuri appears in the crossover game, Project X Zone, a collaboration between Capcom, Sega, and Bandai Namco Games, alongside Estelle and Flynn. Estelle is his partner character, who assists in his combos directly, while Flynn is an assist character, who can be called upon at any time to increase damage and combo potential. Yuri retains his mystic arte as his finishing move. Yuri and Estelle's introduction level is inside the Fujisakura in Kaguya Nanbu's hometown of Kagura Amahara, immediately after being warped from Halure's tree. They have a brief battle with Sanger Zonvolt from Super Robot Wars: Original Generations to prove themselves "worthy" in his eyes before the rest of the X Zone team shows up to help them deal with a massive monster ambush.
Project X Zone 2: Brave New World
Yuri appears in the sequel, with Flynn as his partner instead of Estelle. Yuri's introduction is during the game's final prologue, in which he and Flynn team up with Valkyrie from Valkyrie no Bouken and Chrom and Lucina from Fire Emblem Awakening to defeat Valkyrie's longtime nemesis, Kamuz the demon ogre.
Yuri appears as a Pair Unit teaming up with Lloyd Irving.