Sawatari comes from money—his father's a high-ranking official in Maiami City—and he's a student at Leo Institute of Dueling. He's best known for his rivalry with Yuuya Sakaki, which started after losing to him and vowing to get revenge. That loss actually changed him more than he'd probably admit.
Early on, Sawatari's the textbook arrogant duelist. He calls himself a "Perfect Duelist" and lives up to the stereotype: selfish, pompous, loves the spotlight and his crew's praise, and genuinely doesn't handle being interrupted well. His loss to Yuuya stung his ego hard, but it also sparked something in him—he started picking up some of Yuuya's mannerisms and actually began caring about entertaining the crowd. Fans often note his habit of making dart-related gestures when he thinks they fit the moment.
Personality-wise, Sawatari's shallow about a lot of things. He's extremely materialistic and only cares about rare cards, which shows in his decks—they're loaded with Parallel Rares. When it comes to card effects, he pretty much ignores them and just looks at ATK, DEF, and Level. He's also not above using his father's position to get what he wants, whether that's threatening to have someone fired or pulling strings behind the scenes.
Content compiled by AnimeList.moe from publicly available sources.