The premiere episode of "Bet" unfolds with an exhilarating introduction to Yumeko, who triumphs in a gambling match amidst detention duties. The school principal's unexpected arrival catches her in yet another gambling spree, promptly leading to her expulsion. Her guardian soon appears to collect her, promptly revealing that Yumeko's dismissal was actually a premeditated maneuver—a preemptive strike to have a convenient alibi handy should anyone delve into her past.
Scenes shift as Yumeko arrives at the prestigious gates of St. Dominics, an elite institution catering to the ultra-wealthy and influential, where teachers wield little authority and students bear no consequences for their actions.
Elsewhere within the school's hallowed halls, a high-stakes gambling match is in full swing. Ryan, a student participant, finds himself bested by Mary, who resorts to underhanded tactics, swiftly swapping cards to secure her victory. With Ryan now saddled with debt, he becomes her "house pet," utterly under her thumb.
As the crowd dissipates, Ryan encounters Yuki, the newest addition to their ranks, in the hallway. He fills her in on the school's unique dynamic, where gambling reigns supreme. Students wager their monthly allowances freely, and the top ten gamblers are rewarded with a coveted seat on the student council, signified by their distinctive black jackets.
The Student Council wields dominant control over the school's games, with an undeniable upper hand. Ryan introduces the esteemed council members: Dori, Mary, the influential Suki, Riri, and at the helm, Kira, the President whose father commands the board of parents fostering a fiercely competitive atmosphere, thereby enabling Kira's grip over the school.
Entering her dormitory, Yumeko strikes a wager with her roommate Blake, daring him to voluntarily swap beds with her by day's end. Her audacious challenge sets the stage for an encounter with the council, where Yumeko issues a duel to Mary. Ryan, alongside the reclusive and gambling-averse Michael, caution Yumeko against engaging in the contest.
Memories of Yumeko's gambling escapades with her mother, who exhorted her to find delight and excitement in such pursuits, flash through her mind. As Yumeko and Mary clash in a card game, her keen eye detects deceit – Mary is utilizing Ryan, positioned behind her opponent, to relay card signals. Yumeko, raising the ante to a quarter-million-dollar stake, declares she will award half her winnings to Ryan if victorious. In the end, Mary's defeat turns her into Ryan's submissive companion, as Yumeko gracefully declines taking one. Consequently, Ryan's debt is liberated.
Back in their room, Blake, captivated by Yumeko's day's exploit, honors their bet and switches beds. Ryan seeks Yumeko out for a chat. A haunting flashback unveils the tragic moment Yumeko witnessed her parents' demise in a fiery car explosion. The episode culminates with Yumeko's chilling proclamation: she is playing not just for the thrill, but for retribution, embodying a relentless pursuit akin to "playing for blood."
