Yugo appeared in the first installement, Bloody Roar. He is considered to be the main protagonist for the series, and he's often viewed as the series' character mascot.
Yugo was the son of the mercenary, Yuji. One day he is informed that his father has been killed while out at war. Yugo starts to doubt the circumstances of his father's death and decides to investigate it himself. It's at this point he comes to learn that he is a Zoanthrope and that his father was involved in a conspiracy with a multinational corporation called Tylon. To find out the secrets behind Tylon and to find out what actually happened to his father, he sets out against the evil company. He's joined by a old Yuji's friend and brother-in-arms, Gado. They break through into a hidden lab in the Tylon building where many large cylinders lining the room with test subjects inside. Yugo cannot find his father, and by Gado's reaction, he can tell that Tylon had already killed his father. He at least now knew the truth of how his father died. Standing over a makeshift grave a top a hill, he vows never to let it be over.
Bloody Roar 2
Back To The Battlefield
After the fall of Tylon, Yugo hides his Zoanthropy and takes up a career as a boxer. He is not truly alone, as he took under his wing a boy that he found during the destruction of Tylon. The boy had no memories and nobody to take care of him, so Yugo took it upon himself to adopt him as his brother and named him Kenji. One day, five years after the incident with Tylon, Kenji is mysteriously abducted by a terrorist group leads from a strange man named Busuzima who seriously beat him up into a bloody pulp while he abducts Kenji away from him after his boxing match. He was later taken to the hospital where his childhood friend Alice who works as a nurse. Alice tries to treat Yugo's serious injuries but he angrily refuses and quickly leaves the hospital to save his brother while in his injured state that forces Alice to follow him and takes him back for treatment. He learns by Jenny, a mysterious woman, that Kenji is taken prisoner by the ZLF, the terrorist organization. Later on, he meets Busuzima's former partner and scientist, Stun and also mistakes him that he is working with the ZLF. After defeating Stun, he apologizes for beating him as he tells him that the ZLF abducts live Zoanthropes as their experiments. This makes Yugo becomes overprotective to his brother and does not want his brother to become a terrorists like them. He then asks the location of the ZLF headquarters. Stun tells him that he's already been in the headquaters but it was too late for him. Yugo continues his research and, he finally finds Kenji but he's brainwashed by Busuzima and became his bodyguard. After a fight against his brother, Kenji retreats to the ZLF headquarters making Yugo follows him. Arriving at the headquaters, he finally found Busuzima who is experimenting other live Zoanthropes and reveals to him that he brainwashed Kenji to become Bakuryu the cold blooded ninja assassin as the original and orders him to eliminate Yugo as the latter was then forced to fight his brother for another round. After defeated his brother the second time, Kenji regains his mind and Yugo was relieved and finally confronts Busuzima for what he had done. He then orders Shenglong to deal with him. Yugo recognizes him as Long but he states that his smell was different than the real Long and fights him. After defeating Shenglong, Busuzima finally fights him after his bodyguards were defeated by him. Yugo brutally defeats Busuzima into a bloody pulp and finally convinces his brother to get home and Kenji became mortified that Busuzima made him a ninja assassin. He then tells him to live a normal life just like him as he goes with him. On the way back, Gado comes to them and convinces Yugo he is the perfect candidate for the position as the leader of a new group that would support the peace between humans and Zoanthropes. That it's his generation that will make a difference. Yugo initally refuses the position as Gado fights him. Yugo managed to defeat Gado and he stated that he is the perfect candidate whether he likes it or not and convinces Yugo to become the leader even his brother Kenji also convinces him to be the new leader after he saves him from Buzusima. He reluctantly accepts the position and stating that he will try to do whatever he can as the leader of the new group. He and his brother helps Gado in his injured state from the burning ZLF headquarters. Along with his brother, Yugo sets out as the new leader of a group that sets out to pave their way to a bright future.
Bloody Roar 3
Yugo becomes the leader of an NGO (Non-Government Organisation) called the W.O.C. (World of Co-Existence). Their goal is to build a bright future for both humans and Zoanthropes alike. But a mark known as the 'XGC' appears on his body. The 'XGC' will eventually end his life and end the lives of others who are afflicted if he doesn't find out how to stop it. He sets out to uncover the truth about the tabula, the mysterious cause behind the mark. Yugo sets about destroying the object, previously Xion's possession, so that the XGC mark will disappear from the bodies of the Zoanthropes. Now the ordeal is over, he returns home to be happily greeted by his brother and friends - especially Alice, who lets him know how much she misses him as she leaps at him with a hug.
Bloody Roar: Primal Fury/Extreme
A representative of the Zoanthrope tournament visits Yugo. Prior to his visit, a group of thugs had attacked Yugo as part of a test to show the representative his legendary skills. Yugo had worked out for himself who they were working for. The man gives him an invitation to the tournament. Yugo accepts, wanting to learn more about the 'bad' activities that were going on behind the scenes. His investigation lead him to Cronos, the prince of the Kingdom of Zoanthropes and opponent in the tournament. Yugo defeats him in the Tournament final. Cronos then begins to glow, a greater power emanating from within. Yugo tells him to get up. He doesn't believe the fight is yet over. Red beams of light pierce through the darkness. He looks over his shoulder as Gado enters the lab with armed forces. Yugo thanks him but says he can handle things. He steps up to Cronos, who looks up at him breathlessly. A soldier cocks a gun but Gado raises a hand to indicate he should wait patiently. Yugo and Cronos stare eye to eye before abruptly squaring off and lunge toward each other. Later, Yugo overlooks the palace atop his motorcycle. He smiles to himself before revving the engine and riding off into the sunset.
Bloody Roar 4
Yugo has been racking his brains over the violence occurring. While out investigating the incidents he heard rumors of a 'Black Shadow'. Also, that the name of this 'Black Shadow' was Nagi. This name he'd heard before. He was sure she had been a victim during the incident with the XGC a year before and was still in a hospital somewhere. In order to learn the truth, Yugo sets out on a journey after Nagi, but eventually meets Ryoho and Mana, suddenly Ryoho becomes a dragon Zoanthrope and attacks Yugo. After defeat him, Mana reseals the dragon, she verbally supports Yugo's assumption of the dragon's power causing the earthquakes and violence. She makes a final call and the seal is complete. Mana thanks Yugo for his help in the resealing. He asks what the connection was with the Unborn. She explains to him that the dragon was created by the life force of the planet itself with a purpose to protect the world and rid it of evil beings and beings that threatened to harm the world. He asks if it was the dragon that was holding back the Unborn all that time ago? She confirms this. It confuses him why Nagi has become loyal to the Unborn. Mana informs him of her powers being a copy of the Unborn's, though unfortunately along with the powers the spirit was copied as well. He understands that she was taken over. Proudly, he exclaims he must be pretty strong to have defeated such a strong dragon. She's quick to inform him that the seal wasn't fully broken, so that was only some of its power he experienced. She looks mournfully, admitting if the seal had completely broken off then she wouldn't have been strong enough to stop the dragon. Yugo takes in what she says, and tells her he wants to fight a dragon with full strength one day. Horrified, Mana tells him he can't. Yugo starts to laugh, admitting that he was only joking and not to look so scared. Somewhat relieved, she scolds him for his joke. At that moment, Ryoho begins to make sounds indicating he is starting to stir. Yugo points out the 'old man' is waking up. Mana gives Ryoho a happy good morning as he sits up, asking if he slept well. Grumbling groggily, he mutters that he guesses so.
Yugo is very aggressive, impulsive and short tempered; he is also somewhat childish and very upbeat, as seen in Bloody Roar 4 when in every scene he smiled cheerfully and also Yugo has some heroic tendencies. Despite his hot-tempered nature however, Yugo is actually a caring and kind-hearted man who hates injustice and will always lend a hand to anyone who needs it. Yugo is also very protective of his level-headed brother Kenji. He is very playful around him, as seen in Primal Fury and Extreme, putting Kenji in a playful noogie in Kenji's ending.