Anime Couple: Yugioh ARC V :Yuya x Yuzu

YUYA SAKAKI X YUZU HIRAGI
Zuzu is Yuya's closest childhood friend and love interest. To Yuya, Zuzu is an irreplaceable figure in his life and he cherishes her greatly. As she is someone who has always been with him. Zuzu is supportive of Yuya and would help him whenever he is in trouble by defending him when someone may try to insult him. Zuzu also acts as a "straight man" in a comedic act with Yuya, usually beating him with her paper fan whenever he angered her. Behind this however, she harbors romantic feelings for Yuya. These feelings are made apparent when Zuzu blushed when Sora mistook her as his girlfriend, when she accidentally hugged Yuya which caused her to push him away in panic, and jealous whenever Aura makes advances towards him or calling him "darling". Earlier in the series, Yuya had only thought of her as his close friend, evidenced in that he protested at the prospect of dating a crude strong girl like Zuzu when Sora mistook her as his girlfriend. However, even at this point his feelings for Zuzu were no less caring as he cries when he realizes Zuzu was gone after Duel Academy attacked Paradise City (unaware that she teleported to another dimension with Yugo previously).

As the series has progressed, it has been evidenced that Yuya likely returns Zuzu's feelings and looks at her as more than just a sister/friend. Even as Celina was about to be teleported away back to the Fusion Dimension, Yuya did not move away from Zuzu's side, and not long after he made the heartbreaking decision to abandon his Dueltainer/smile philosophy so long as he could successfully protect Zuzu and make her smile. This was especially symbolic as he discarded "Smile World"; the symbol of his ideal, to free Zuzu from Sergey's cards. His failure to protect her in this instance caused him to passionately fight to rescue her from Jean-Michel Roget and upon doing so, he hugged her warmly after reuniting with her in the Synchro Dimension. He became emotionally shattered and heartbroken after he heard and then saw Zuzu under the control of the Doktor, which caused him to Awaken for the first time on his own accord and he was overjoyed when Zuzu regained her mind after she was freed from the Parasite Monster's control. Whilst Zuzu was kidnapped and being fused with her counterparts in the Revival Zero project, Yuya tried to fight his anger for her, so as to not Awaken. However after seeing the process begin to intensify, and hearing her pleas for help, he gave into his anger in an attempt to save her. Furthermore, his incredibly strong feelings for her are reinforced after having remembered Zuzu in the "Pendulum Dimension" and the fact she wasn't there, which made his happy demeanor shift immediately to one of inner turmoil and absolute despair, along with tumultuous guilt at the fact he had not remembered her sooner.

Yuya is also supportive of Zuzu and is grateful for all her help over the years. When she is depressed, Yuya always gives his encouragement to steer her spirit. Yuya's bond with Zuzu is shown to be very deep, as shown during the aftermath of Battle Royal, Zuzu is the one whose well-being Yuya cares the most for as he stated how Zuzu is the one who is always by his side from the very beginning and it was also thanks to her he was able to grow his Pendulum Summoning. If one of them is depressed, the other is usually the one to cheer them up. This bond culminated in Zuzu's speech to Zarc that she believed that Yuya was not a demon despite being the reincarnation of the destroyer of the Original Dimension, allowing for Yuya to break free of Zarc's control and allow Ray/Riley to defeat him. It is therefore likely to assume, that the two do have a mutual affection and love for one another.
SOURCE: YUGIOH.WIKIA.COM