Yuuya Sakaki is the main protagonist of Yu-Gi-Oh! Arc-V. He is a born-entertainer who attends the You Show Duel School to advance his duelling expertise and become an "Entertainment Duellist," a specific type of professional duellist similar to his father.
He has three known dimensional counterparts: Yuto (from the Xyz Dimension), Yuugo (from the Synchro Dimension), and Yuri (from the Fusion Dimension). According to Yuzu Hiragi, he and his counterparts are drawn to each other. He later became one of the Lancers that Reiji Akaba setted up, in order to defend from an invasion from Academia in the Fusion Dimension.
(Source: Yu-Gi-Oh! Wikia, edited)