Episode 4 of "Bet" kicks off with Yumeko on the brink of contemplating Raymond's demise, yet she swiftly reels herself back from the abyss of her dark thoughts. Still reeling from their harrowing encounter, her distraction deepens, ultimately leading her to craft a prototype explosive in the serene confines of the library—a discovery that Michael unwittingly stumbles upon later.
Elsewhere, an enigmatic side wager begins to ripple through the school's corridors: a bold bet on Ryan's virginity. Kira, sensing a delicate orchestration behind this chaotic spectacle, delves into her suspicions with her sister, Riri, who, coincidentally, receives a missive from their father at that very moment.
The bet ignites a frenzy across the school, with both genders shamelessly vying for Ryan's affections, driven solely by the promise of swift monetary gains.
Within the library's hushed embrace, Yumeko unburdens her soul to Michael, recounting the harrowing tale of her parents' demise—their car bursting into flames right before her eyes, the tense altercation they had with an unseen figure moments before. She then implores Michael to assist her in refining the bomb she has been tirelessly working on.
Meanwhile, Mary devises a cunning plan. She somehow secures a loan and places a bet on Ryan's virginity herself. Her devious scheme? To pretend that she and Ryan shared an intimate moment, preserving his dignity while she walks away with the lucrative prize. However, Ryan steadfastly refuses, his heart ensnared by Yumeko.
The day of the school recital dawns, an occasion where Blake is poised to shine, prompting her stepfather, Raymond, to visit the school's hallowed halls. Blake, enveloped by a cloak of anxiety, nearly dismisses him, but Yumeko persuades her to allow him to stay and give her all, especially since Michael has vowed to lend a hand—but only if Raymond is the target of their hidden agenda.
Later on, Mary pressed Yumeko to consummate her relationship with Ryan as an escape route from the virginity wager chaos. Yielding to the pressure, Yumeko ventures into Ryan's chamber, but her resolve falters when she realizes that their affections are not mutually shared. Respecting her own heart, Ryan decides against forcing the issue.
Inside the auditorium, Yumeko orchestrates Raymond's seating arrangement meticulously, positioning him directly on a chair she had surreptitiously rigged with explosives. Despite her meticulous planning, the assassination attempt crumbles when Yumeko discovers Michael's deceitful hand in the scheme.
In a confessional moment, Kira reveals to Yumeko that she was the mastermind behind the virginity wager targeting Ryan. Her motive? To jolt the increasingly slackening student council back to attention and reclaim her authoritative stance.
Driven by desperation, Yumeko trails Raymond, powerless to intervene as he steps into a car alongside Blake. A heart-stopping instant later, the vehicle detonates in the horizon, and Yumeko's lips curl into a grim satisfaction.
However, the episode concludes with a stunning revelation: it was Riri who actually planted and ignited the bomb, clutching a letter from her father as she gazes thoughtfully out the window, revealing a depth of intrigue and duplicity that leaves the audience breathless.
