Sayaka Sasayama

Sayaka Sasayama (サヤカ, Sasayama Sayaka) is a character in the Yu-Gi-Oh! ARC-V anime. She is a friend of Allen Kozuki and is a surviving resident of the Xyz Dimension as well as one of few remaining members of Resistance.

Past
Before Academia's invasion, Sayaka, together with Allen and Kaito Tenjō, were students of Heartland Duel School's Clover branch who studied under Yūshō's guidance, who was the teacher of their branch. One day, Academia attacked and nearly annihilated the entire population of Heartland City. During this invasion, Yūshō suddenly disappeared, leading them to believe that Yūshō had abandoned them. While Shun and Yūto went to Standard Dimension to look for Reiji, the Resistance continued to fight. Despite their best efforts, both Spade and Clover branches were nearly wiped out, forcing them to be in hiding.

Yūya vs. Kaito
Sayaka and Allen were reunited with Shun, who got transported back to Heartland along with Yūya, Gongenzaka, and Shingo. The three of them then looked for Yūya and the others, arriving just in time to stop the Duel between Kaito and Yūya. Together with Shun and Allen, she assured Kaito that Yūya and the others are a few allies that Shun brought with him to help them. Sayaka asked Kaito to return and fight together with them again, but Kaito refused and left the scene.

Resistance Hideout
Back at their hideout, Sayaka helped in distributing foods for the refugees even though it's not her shift. Allen told her not to overwork herself and told her to rest, something that Sayaka reluctantly relented. Sayaka then listened to their discussion and revealed that Kaito's entire family had been carded by Academia while Shun and Yūto were away. While Yūya was lamenting over this, she remembered Yūya's last name and asked does he has any connection with Yūshō, explaining that Yūshō was their teacher and disappeared during the invasion, and Allen believed that Yūshō has abandoned them.