Before the catastrophic events unfolded, Haiji Towa stood as the firstborn son of Tokuichi Towa and his wife, poised to inherit the leadership of Towa City. In stark contrast, his younger half-sister, Monaca, was born into a world that deemed her unwanted. Abandoned by her mother shortly after birth, Monaca faced a bleak future until Tokuichi decided against sending her to an orphanage, instead welcoming her into their home. However, Haiji's treatment of her was far from kind; he harbored a deep-seated resentment towards Monaca, feeling a wave of sickness wash over him whenever she affectionately referred to him as her big brother. His instincts screamed that she would ultimately bring ruin to their family. Despite his disdain, Monaca's brilliance propelled her to the forefront of Towa Group's robotics division, eclipsing Haiji's own achievements and fueling his bitterness. In a shocking turn of events, Monaca allied herself with Junko Enoshima, deceiving her father, brother, and the other adults with promises of creating advanced robots designed for domestic assistance and emergency response. Her separation from the family, coupled with her extraordinary intellect, led them to grant her the freedom to pursue her ambitions, as long as she delivered profits without probing too deeply into her true intentions. However, the robots she developed would soon unleash chaos upon the city, culminating in the brutal death of Haiji's father and the loss of his arm. Meanwhile, Haiji found himself leading the adults' Resistance, a group forced to hide in the sewers from the relentless Warriors of Hope. Stripped of everything he held dear, including Towa Group and Towa City itself, he claimed to be biding his time for a chance to retaliate. Yet, deep down, he was consumed by despair, surrendering to the hopelessness of their situation. Paranoia gripped him as he ensured that no one could escape their underground refuge. Now, Haiji sits in his office, consumed by thoughts of reclaiming the city that once belonged to him.