Synchro Dimension Arc

Synchro Dimension Arc is the second story arc of Yu-Gi-Oh! ARC-V anime series. It follows Yūya and his friends' struggle in City of Synchro Dimension to gather allies and facing the threat from Jean-Michel Roget, a former Academia agent who became the Director of Security and plans to turn Synchro Dimension into his own personal kingdom.

Arrival
Yuzu, who got transported to Synchro Dimension with Yūgo, learned that Rin is Yūgo's childhood friend who was kidnapped by Yūri, and he mistook Yūto as Yūri when he met the former in Heartland, leading to their clash. After clearing up the misunderstanding, Yuzu explained what she knows about Academia. The two were interrupted by nearby people who were referring them as Commons and both escaped. Yūgo explained that in City, there are two social classes: the poor is called Commons while the wealthy is called Tops. There also exist Riding Duel, a Duel that is done by riding a motorbike-like vehicle functioned as Duel Disk called D-Wheel. To promote peace between Tops and Commons, a tournament called Friendship Cup is held, and the one who continuously won will earn the right to challenge the Duel King, Jack Atlas.

The two were chased by Security, a group functioned as police force for Tops. The member of Security, Duel Chaser 227 challenged Yūgo to a Riding Duel, which Yūgo accepted and he easily won after summoning his ace monster "Clear Wing Synchro Dragon", and he and Yuzu successfully escaped. The Duel earned attention from the Director of Security, Jean-Michel Roget, who ordered for the Security to look and capture the two at sight.

The next day, the Lancers arrived, but they got separated from each other. Yūya, Serena, Reira, and Shingo arrived at Commons area and were found by Security. Mistaking Yūya and Serena as Yūgo and Yuzu, they challenged them to a Duel. Overwhelmed by numbers, Yūya and the others were surrounded until they were saved by the arrival of Crow Hogan and his friends who allowed them shelter until they found their friend. However, when Serena and Shingo went out to duel people nearby to find potential allies, Security found and secretly followed them, leading to their capture together with Crow and his friend, Shinji Weber. Reira, however, was saved by Tsukikage before he could be captured.

Meanwhile, Dennis and Gongenzaka were invited by a man named Gallager after he witnessed their Duel when the two tried to earn money. He took them to an underground Riding Duel where it turned out Shun was participating so he can earn the right to enter Friendship Cup, hoping to gain powerful allies against Academia. Shun and Dennis clashed against each other after a brief argument, and Shun started to get suspicious of Dennis' true identity during their Duel. Their Duel was stopped when Security raid the place and they were under arrest.

The Facility
Yūya and his friends were taken to a camp called the Facility, where they reunited with Gogenzaka and Dennis, while Serena and Shun were taken to solitary confinement on their first day: Serena taken there under Roget's order, while Shun after he got into a fight with other inmates. There, they learned that card functions as money, which means if they want to be treated nicely they have to give their cards to the guards as bribery. Yūya and the others earned the attention of the Facility's "leader", Chojiro Tokumatsu, who demanded them to give them their cards to him if they want to live in luxury. Refusing to do his biding, Yūya challenged him to a Duel to remind him how Dueling is supposed to be fun for everyone, a feat that Yūya succeeded.

A few days later, Crow, Shinji, and their friends decided to stage a jailbreak by using the Grand Entertainment Duel that Tokumatsu will hold with Yūya and Shingo as diversion. Not wanting to trouble Yūya and his friends, Crow acted cold towards him so he won't be punished if they escape. During the Duel though, the Lancers finally able to convince Crow to let them escape together. With Tokumatsu and other inmates help, they succeeded getting out of the Facility, but now facing against the Arrest Corps. When it seemed they successfully escaped from the corps, they got caught by Roget who lured one of Crow's friend into a trap. Before they can be taken back to the Facility, the Executive Council of City asked for the escapees to be taken to them.

Reiji turned out to have already explained the whole situation to the council regarding the reason of Lancers' arrival and Academia's incoming invasion. To prove their worth as allies, the council tasked them to enter Friendship Cup where their skills as Duelist will be tested. Following this decision, Roget suggested for Yūya to Duel Jack in the tournament's exhibition Duel. Initially refusing to participate, Yūya reluctantly agreed after learning that Yuzu also participated in Friendship Cup, having been registered by Yūgo who thought it would be easier for her to warn of Academia's invasion.