In 2008, middle school student Kurumi Fukuga’s life is shattered when her mother, Kozue, secretly loses 20 million yen of the family’s money through foreign exchange margin trading (FX) following the bankruptcy of Lehman Brothers. Unable to bear the weight of her financial disaster, Kozue dies by suicide. Vowing to reclaim the lost fortune and give meaning to her mother’s death, Kurumi becomes obsessed with the world of FX. She spends her high school and early university years studying the market, determined to easily earn back the money.

Years later, in 2014, a 20-year-old Kurumi finally makes her long-awaited debut in FX trading. She enters a ruthless financial battlefield where fortunes can reverse in an instant, a world that can switch from heaven to hell at the flicker of a chart. Driven by the singular goal of recovering her mother's debt, she quickly discovers that the market is a brutal psychological test. The pressure of unrealized losses, the terror of forced sell-offs, and the constant, pounding heartbeat of high-risk decision-making push her mental limits to their breaking point.

Kurumi is joined by other eccentric FX fighters. Mochiko Kogane is an academic prodigy from Kurumi's university whose own difficult past leads her to take an interest in Kurumi's trading activities. Mebuki Yamashi is another trader who becomes associated with the group, and Yasuko Takane is an aspiring creator who previously ran a finance blog before suffering her own devastating financial losses. Together, these women navigate the volatile and often toxic culture of margin trading, where confidence can vanish overnight and bad trades can be influenced by dangerous company.

The story follows Kurumi’s volatile journey as she experiences the highs of early successes and the crushing lows of significant losses. After her father Ikuo, who had warned her against FX following her mother’s death, discovers her secret trading, she is forced to quit. However, she finds she cannot stay away from the market’s pull and eventually resumes her activities. The narrative tracks her psychological deterioration from a hopeful student into a desperate gambler, charting her attempts to survive the chaotic world of currency speculation and her struggle to control the very forces that destroyed her family.