Yūya Sakaki/Relationship

Yūshō Sakaki
Yūshō is Yūya's father and one of major influences in Yūya's growth as Duelist. Yūya greatly loves and admires his father and dreams to become a professional Entertainment Duelist like him. It is also through Yūshō's dueling Yūya developed his belief that dueling is for fun and makes people happy. Despite his father's sudden disappearance, Yūya continues to respect and admire his father, believing there's a reason for his disappearance and dislikes when someone make a fun of his father. Consequently, Yūya's admiration for his father caused him to unconsciously becoming obsessed on following his footsteps, resulting Yūya to imitate his father's Dueling style that Yūya thought as simply being inherited to him. Yūya was oblivious of this fact until his Duel against Jack in the Friendship Cup final match, where he finally realised that while his father’s thoughts are a part of him, they do not define him as a whole and he can still follow the beliefs and principles set up by his father but not limiting himself by copying him, allowing Yūya to leave his father's shadow while still carrying his will. Yūshō also loves Yūya dearly, and this feeling doesn't change even after knowing that Yūya is not his real son and his origin as the reincarnation of the Demon Duelist. He continues to believe in Yūya and willing to sacrifice himself to protect his son.

Yōko Sakaki
Yōko is Yūya's mother. Although not as close as Yūya did with his father, Yūya is also in a good relationship with his mother like a normal mother and son. Yōko understood how her son was feeling when his father disappeared and is supportive of Yūya's dream to become a professional Entertainment Duelist like his father. She would help and take care of Yūya in any way she can when he is in trouble, as shown when Yūya was unconscious for two days and challenged him to a Duel to help him regain his spirit. However, Yūya is often flustered whenever his mother's fondness for cute boys get the better of her. When this get the better of her, she doesn't hesitate to cheer them such as Michio and Dennis rather than her own son. When Sora successfully pleased her with his sweet-talk, Yōko takes care Sora more, almost not minding Yūya.

Yuzu Hīragi
Yūya and Yuzu are childhood friends. Yuzu is supportive of Yūya and would help him whenever he is in trouble and defending him when someone make insulting him. Yuzu also acts as a "straight man" in a comedic act with Yūya, usually beating him with her paper fan when he angered her in any way. Behind this, she harbors feelings for Yūya more than just a friend. This feeling is made apparent when Yuzu blushed when Sora mistook her as his girlfriend, she blushed heavily when accidentally hugged Yūya that caused her to push him away, and jealous if Mieru makes advances towards him or calling him "darling". Unfortunately for Yuzu, Yūya is oblivious of her feelings towards him and so far only think of her as his close friend, furthered by the fact that he protested at the prospect of dating with crude strong girl like Yuzu when Sora mistook her as his girlfriend. Her feelings for Yūya is also what drove her to become stronger so she can protect him and the others. Whenever feeling Yūya is in danger, she doesn't hesitate to place herself in danger for his sake.

Yūya, on the other hand, is also supportive of Yuzu and is grateful for all her help for years. To Yūya, Yuzu feels like an older sister and he cherishes her greatly. While so far Yūya doesn't reciprocate her feelings more than just a friend, to him, Yuzu is an irreplaceable existence who always stay by his side from the very beginning. When she is depressed, Yūya always gives his encouragement to steer her spirit. Yūya's bond with Yuzu is shown to be very deep, as one of his main motivations to fight and put an end to the inter dimensional war is for her sake.

Noboru Gongenzaka
Yūya and Gongenzaka have been friends since they were kids and share a very close bond. After his father disappeared, Gongenzaka always defended Yūya from bullies and is very protective of Yūya. Not only defending him from bullies for years, Gongenzaka also helped Yūya on finding an opponent for Duel with his dōjō's connection, something that Yūya is very grateful for. His friendship with Gongenzaka made Yūya at first hesitated when he has no choice but to duel with him to enter Maiami Championship out of fear it would make Gongenzaka lose his chance to enter as well. Gongenzaka cares for Yūya and worry whenever something happened to him, usually giving him a hug after he is confirmed to be fine.

Futoshi Harada, Tatsuya Yamashiro, and Ayu Ayukawa
Yūya acts as a older brother figure to the three of them, continuously supporting them to improve their Dueling skills. In return, Futoshi, Tatsuya, and Ayu admires Yūya whom they called "Yūya-onīchan" and also supporting him in return. Though, they sometimes also like to tease Yūya in some way, one of such is how Yūya is oblivious about Yuzu's feelings towards him.

Shūzō Hīragi
Yūya respects Shūzō as his teacher and his father's close friend, always referring him as "Principal". He usually asking him for advice when he is confuse on how to proceed with his Duel. Like everyone else, Shūzō has high hopes for Yūya to follow his father's footstep and succeed him as an Entertainment Duelist, seeing him as one of his best students. Shūzō sometimes also gives Yūya an errand such as picking up Yuzu when she spent most of her times to train Fusion Summon with Sora, much to Yūya's dismay. Shūzō is confident in Yūya's skill as Duelist and trust him enough to save his daughter after hearing of her disappearance.

Sora Shiun'in
Yūya at first was annoyed and flustered when Sora followed him everywhere and insisted for him to make Sora his apprentice, but they eventually get along well. Yūya thinks Sora as a dear friend and cares for his well-being, defending him when he appeared to be in trouble and expressed concern when he was injured. Sora, on the other hand, admires Yūya after he saw his match and insisted to be his apprentice, but then decided to become his friend after he lost in the Duel. Sora has shown great interest towards Yūya for many of his achievements in Duels that he claims to always be beyond his expectations. However, while Sora still thinks of Yūya as his friend and truly thinks that dueling with Yūya is exciting, he avoids it for his beliefs as one of Academia Duelists and its noble cause, stating that to him his loyalty for the Academia is stronger than their friendship. But this began to falter when Sora found out that Yuzu has been targeted as well, leading Sora to finally admitted that he truly thinks of Yūya as his precious friend. To avoid him from harm, he even tried to convince him to drop out from the war and vowed to rescue him when he was captured by the Security, which also leads him to finally betray Academia. In return, despite seeing Sora change people into cards in front of his own eyes, Yūya still considers Sora as his friend and is determined to make Sora smile and enjoy Dueling like when they first Dueled. After knowing Sora's true feelings, Yūya chose to put his faith on Sora to protect Yuzu, believing that he won't hand over Yuzu to Academia because they are friends.

Yūto
Although they both had only met for a short time, Yūto developed a strong trust towards Yūya who shares the same belief as him. This is what made Yūto entrusted Yūya with his "Dark Rebellion Xyz Dragon". Yūya, on the other hand, was initially wary and skeptical of Yūto, but Yūya eventually understood that Yūto actually doesn't want to hurt anyone. Even though Yūya doesn't understand what Yūto expected from him, Yūya resolved to make people smile with Dueling like Yūto told him to. Yūto's last words to him occasionally became a reminder of Yūya's Dueling belief. After experiencing the possession caused by Yūto's anger and sadness, Yūya started to understand Yūto's suffering and opted to believe in Yūto who wishes for peace instead of blaming him for the consequence of his brutal Dueling method. However, Yūto sharing his memories and desires with Yūya has severely traumatized him as shown by his reaction to the memories of Heartland being invaded and all the people being carded. Despite this, without the two of them realizing, the two formed a strong bond with one another. While Yūya's promise with Yūto became one of Yūya's primary motivations to continue dueling, Yūto trusted Yūya as a comrade that will never betray his friends. Yūto is also shown to be protective of Yūya, seen when he took control of Yūya's body when he was cornered during his duel with Isao and defended him from Shun's accusations while merged with Yūya. In return, Yūya is also protective of Yūto, immediately telling Reiji to stop when the latter was about to bring up the tragedy of Xyz Dimension, knowing it traumatized not only Shun, but also Yūto within him. During their battle at Synchro Dimension Yūya came to understand Yūto's rage, and Yūya's Entertainment Duel against Jack managed to reach Yūto's heart, strengthening their friendship further. Unfortunately, Yūto's protective nature and hatred for Academia sometimes could get the better of him, resulting Yūto to lose confidence in Yūya's ability to win, and their philosophy of making people smile through dueling, to do whatever it takes to defeat his opponent so he can protect his comrade, even if Yūya pleaded to him not to. By the time Yūya was able to finally change Edo's heart, Yūto's confidence in Yūya returned.

Serena
Both so far were rarely seen interacting much with each other. However, in the manzai episodes, both are on friendly terms with each other. Yūya tried his best to befriend Serena, though this wasn't easy at first due to Serena's lack of interaction with other people outside Academia. But they eventually shown to become closer as Serena often picked Yūya's side over Shingo and encouraged him not to give up. From each of their reaction in the series so far, it can be assumed as a fellow member of the Lancers, Yūya generally gets along well with Serena. She, likewise, views Yūya as a comrade and friend. She was sympathetic to Yūya's loss of Yuzu since she was partly responsible for the incident, so she vowed to Yūya that she would help him save her. Though her ego and impatience usually clashes with Yūya's more patient personality, such as when they were surrounded by Security and she ignored his request to escape, both still cares for one another as shown when Dueling against Barrett, Yūya vowed that he will protect her at all cost even when he is cornered by the the former and in return, Serena was concerned over his well-being as she watched him being cornered by Barrett. Although not shown clearly, Yūya's philosophy of bringing smile with Duel also influenced Serena, who never felt the joy of Dueling before. This was shown when Serena used Yūya's "Ladies and Gentlemen" catchphrase once she experienced how fun Dueling can be, making her understood a bit of what Yūya's trying to accomplish.

Reira Akaba
When Lancers arrived in the Synchro Dimension and were split up, Yūya quickly became protective of Reira and made it his goal to make the young boy smile, noticing the boy's shyness and wariness around people who are not his brother. Yūya's concern for Reira's well-being led him to get angry towards Reiji who had ordered Reira to fight despite his young age and knowing how afraid Reira, making Yūya promised that he will protect the boy. In return, although still shy, Reira grew to have an attachment towards Yūya. When Reira was scheduled to Duel Shinji in the Friendship Cup, Reira immediately rushed and hugged Yūya for comfort. Yūya's kindness and determination also one of the factors that inspires Reira to finally stand up for himself so he can be a Duelist like him and his brother. Knowing how depressed Yūya was after his Duel against DC - 227, Reira asked Tsukikage to deliver his message in hope to reignite his spirit and showed his confident of Yūya's skill. Yūya became one of a few people aside from his brother whose presence immediately comforts him. In addition to this, Reira also quickly feels comfortable around people whom Yūya are close with (for exception of Shingo).

Reiji Akaba
Reiji is by far, is Yūya's strongest rival in the series. At first, Yūya held degree of respect towards Reiji for his dueling skill and for defending his father when Yaiba and Hokuto mocked him. However, any inch of respect Yūya had towards Reiji was immediately lost when Reiji revealed that the Battle Royal was a test to recruit Lancers and that he plotted for his friends to fend off the Fusion Dimension invaders, which resulted in many of them being sealed in cards, leading Yūya to believe that Reiji is a ruthless person who only views them as expendable pawns. This was enough to make Yūya Dueling solely to make Reiji repent for what he had done, not even using his Entertainment Dueling against Reiji. After his lost against Reiji, Yūya has yet to forgive him, but begrudgingly work together with him to save Yuzu and those who have been turned into cards. Despite having accepted to join the Lancers, Yūya continues to be hostile towards Reiji, and his opinion of him further soured when he learned how he ordered Reira to join the war. Yūya's trust towards Reiji started to return after Tsukikage reveals Reiji's real character and when Reiji easily guess that he will Duel Jack after hearing Yuzu's broadcast and allowed it. This convinced Yūya that Reiji is different from Roget who only cares of his own well-being, choosing to believe in Reiji despite his blood relation to Leo. Yūya's respect towards Reiji is fully restored after Reiji showed how much he values and trusts him as a comrade, finally allowing Yūya to accept Reiji as his comrade. Reiji, on the other hand, has high expectations of Yūya's potential as Duelist. He has been interested in Yūya ever since he first watched him Pendulum Summoned for the first time. From that moment onwards, Reiji keeps a close observation of Yūya's growth, already considering him to be Lancers candidates before the Maiami Championship even started by arranging for Yūya to be allowed entry to Maiami Championship even though Yūya has yet fulfilled the criteria. His expectation is what made him deliberately provoked Yūya to Duel him in the aftermath of Battle Royal, hoping to draw out Yūya's potential further. Despite rarely interacting with each other, just by the fact Yūya is Yūshō's son and from his own observation, Reiji already understands what kind of person Yūya is, easily figuring out what kind of reactions and actions Yūya would take, such as able to figure out that Yūya will definitely go to Duel Palace to face Jack after hearing Yuzu's plea. Despite Yūya's early hostility, Reiji always considers Yūya as his comrade and is willing to place his utmost trust in him more than to his own father. His faith in Yūya is so strong that he chose to side with him and decides to save him even when he is overwhelmed by Zarc's control instead of defeating him like Leo would do.

Shingo Sawatari
After being defeated in his first duel with Yūya, Sawatari formed a rivalry with Yūya and vowed to defeat him. Due to Sawatari stealing his Pendulum monsters and kidnapping his friends, Yūya in turn didn't like him at all. However, this seemingly changed throughout their second duel in the tournament where both duelist were considerate to one another. After winning a second time, it would appear Sawatari and Yūya became friends with one another and, while they sometimes get annoyed with each other, they seemed to care a lot for each other. This is proved by how Sawatari stormed Reiji's office in an attempt to watch Yūya preform in the tournament after the video feed was cut during the invasion and how he showed sincere sympathy towards Yūya after he lost Yuzu. Yūya also showed surprise and concern when Sawatari lost to the Security in a one-turn kill. Their more friendly relationship is shown later on in the Synchro Dimension when Shingo told Yūya how excited he was to show off their Entertainment Dueling to the Synchro Dimension during the prelude of the Friendship Cup in front of the Executive Council. When Shingo was being taken to the Underground Labor Facility, Yūya was shown to be very upset proving he views Shingo as a friend. Shingo also cares about Yūya enough to angrily acuse Sora of harming Yūya when he saw the two together injured. Yūya also trusted Shingo enough to entrust Reira's safety to him.

Crow Hogan
Crow is the first friend Yūya made in Synchro Dimension. Crow decided to save Yūya and his friends when Yūya protected Reira from Security. Since then, Crow and Yūya have respected one another and see each other as friends and comrades. Despite this, they have gotten into childish arguments about their Dueling beliefs. Crow clearly cares about Yūya and his friends and decided to distance himself from Yūya and his friends when he learned they would suffer the punishment of his plan to escape the Facility just for being associated with him. This greatly saddened Yūya and caused him to become depressed which made Crow realize his method had only hurt his friend more and decided to help him out. When Shinji accused Yūya of being in league with Security and the Tops, he was greatly shocked. Due to Jack Atlas' "betrayal", he didn't know if he could trust Yūya putting a strain on their friendship. However, after his duel with Shun, Crow realized he misunderstood Yūya and his friends. This lead him to apologise to Yūya before their Duel and both vow to help each other as friends. And once realizing that something happened to Yūya during their Duel, Crow placed his own life on the line to bring Yūya to his senses, declaring that because he is also Yūya's friend.

Jack Atlas
Jack is one of major influences in Yūya's growth as Duelist, he is the one who helped him found the Dueling of his own. Yūya and Jack started of at the wrong start, mainly due to Yūya misunderstanding the latter. As a fellow Entertainment Duelist, Jack could sense that Yūya's Dueling was not his own and straightforwardly called it conceited, which Yūya took as an insult to his father's Entertainment Dueling and also deeply hurt Yūya's optimism and belief in dueling. Though Yūya seems to recognize some truth in Jack's words, as during his depression he constantly thought about what Jack told him. Only after hearing Reira's story from Tsukikage that Yūya finally realised the true meaning behind Jack's words. Jack's interest and respect in Yūya started to bud the moment Yūya used "Tuning Magician" to Synchro Summon "Enlightenment Paladin", which revealed that both of them shares the same belief: There's no such a thing as useless card. This made Jack to develop expectation on Yūya, wishing to Duel him again as he hoped that Yūya is the Duelist he has been waiting for.

Jack was momentarily disappointed in Yūya after watching him Awakened during his Duel against Crow (not knowing about the controlling device in his helmet), but he still has high expectation on Yūya, so he requested Sam to deliver his message to him so they could settle their Duel. In response, Yūya determined to answer Jack's expectation. Through their rematch, both mutually realised their wishes thanks to each other's help: Jack finally found an opponent who can truly speak with him through Duel and allowed him to grow as Duelist, while Yūya finally able to forge a path independent of any ties with his father, and become a true Entertainment Duelist as well as ceasing his obsessions in following the footsteps of his father. Settling their score, Yūya and Jack accepted each other as equal. It is from Jack Yūya learned how to communicate with his opponents through Duel, and since then Duels his opponents following this belief to convey his philosophy.

Edo Phoenix
Initially, Yūya and Edo has an antagonistic relationship with each other due to the fact that they are on opposing sides and had different beliefs regarding Duel: Yūya believes that Duel is for fun and should not be used to harm anyone, while Edo believed that Duel is symbol of strength. However, the main problem was due to Edo's one-sided hatred towards Yūshō, who had defeated him, and this hatred quickly extended to Yūya who not only Yūshō's son but also used Entertainment Dueling with the same philosophy like his father. The moment he found out about their blood relation, Edo immediately intended to make Yūya a bait to lure out Yūshō and marked him as his target and won't allow anyone other than himself to get him. During their second Duel, despite Edo's firm insistence, Yūya realised that Edo was actually struggling between his loyalty towards the Professor and the philosophy that his father taught him. At this realisation, Yūya determined to remind Edo how fun Duel is, trying his best to speak with Edo by using Fusion Summon like he did. Yūya's efforts to show how fun Duel can be moved Edo's heart who then remembered the joy and happiness he felt when he Dueled Yūshō, something that he tried to forget. By the time he lost, any contempt that Edo held for Yūya and his father immediately disappeared, defending and joining Yūya to end the dimensional war, and apologised for what he had done. Able to sense Edo's sincerity, Yūya immediately welcomed Edo as his ally with open arms and gives him his trust.

Yūri
Yūri is Yūya's Fusion Dimension counterpart. The two of them initially didn't interact with each other than knowing both are from opposite sides. Yūri's interest in Yūya starts to grow once he came into realization that he and Yūya were originally a same person. From this, Yūri developed strong desire to once again merge wit his counterparts, which includes Yūya. His desire caused Yūri to become possessive of Yūya whom he views as his property and won't give him to anyone. Yūri will do whatever it takes to merge with Yūya, going as far as tormenting Yūshō in front of Yūya to make him lose control of himself and continuously tempts him by tormenting while attacking Yūya in their Duel. Yūya developed quick hatred for Yūri the moment he carded his father right in front of him, which enough to make Yūya succumbed to Zarc's power with only thought of defeating Yūri. After Yuri lost to Yuya, the former gained a degree of respect for him, happy at the fact that Yūya is the first person to defeat him since they are, essentially, the same person.