Born into a wealthy family with a prominent hand in politics, Sadao Isayuki’s life was all but confirmed to be the epitome of comfort and success from the moment he entered the world. The boy’s parents, Masamune Isayuki and Himeka Hirosaki, were the then-incumbent Ministers for Foreign Affairs and Justice respectively within the Japanese government. Greatly fascinated by their dutiful devotion to their country and further influenced by the flawless champions depicted in Saturday morning Super Sentai shows, Sadao developed an obsession with the idea of heroism from a very young age. While this fixation was rooted in good intentions, it would often spur him into taking rash actions without considering the consequences, beginning with regularly coming to blows with bullies at his elementary school.

    During what was meant to be nothing more than a routine vacation to the United States at the diminutive age of eight, an unidentified armed group stormed Tokyo Haneda Airport, taking its patrons hostage with the intent of using the young boy and his eminent parents as collateral in their demands. Eager to finally prove himself as a hero in his own right, Sadao threw all caution to the wind, breaking away from the rest of the hostages and managing to knock over one of their captors – unaware that his target was in possession of volatile IEDs. Both of his parents unfortunately perished in the ensuing blast, alongside the boy himself… as far as the public was concerned. Although Sadao would leave the airport alive, albeit having endured severe blast injuries and mental trauma, family friends within the government chose to withhold this information from the public in order to ensure the boy’s future safety, while taking it upon themselves to pull the necessary strings to piece his life back together.

    Sadao Isayuki died at Tokyo Haneda Airport, leaving behind the charred husk better known as Rouma Hiasobi – a young man convinced of his own inability do good for others and that any such attempt would result in tragedy. The responsibility of overseeing his recovery and raising him now fell under the attendants of his estate, though they would often yield to his whims out of a mixture of respect and pity for his state of being.

    Without much else beyond grieving thoughts to keep him company as he recovered from the Haneda Hijacking, Rouma soon developed an unhealthy obsession with the very explosives that marred his formerly picturesque life. As soon as he was physically able, the boy immersed himself in the unusual hobby of studying the effective usage of bombs and their construction, much to the dismay of his caretakers, though ultimately left unchecked. Soon after entering junior high school, this unhealthy obsession quickly spiraled out of control to culminate in a series of calculated bombings across Tokyo, which while resulting in a great deal of property damage and inconvenience, were also carefully orchestrated to omit any possibility of casualties.

    After effortlessly eluding the local police force for well over a month, the Special Forces Group of the Japan Ground Self-Defense Force was mobilized within the city and soon caught Rouma with his hand quite literally on the detonator. Needless to say, the general public and all parties involved were shocked to learn that a middle school boy was responsible – while censorship surrounding the Haneda Hijacking prevented the release of his true identity, the media was permitted to use the name Rouma Hiasobi and dubbed him the “Chuunibyou Bomber” for his actions.

    Yet still, impressed by the boy's unprecedented talent for guerilla tactics and explosives handling, the incumbent Minister of Defense and JSDF Chief of Staff made the joint decision to conscript him into the Special Forces Group in exchange for the exoneration of all charges weighed against him. Despite the initial legal and humanitarian outrage surrounding this turn of events, Rouma has since earned begrudged recognition over the years as one of the world's most skilled counter-terrorists, whose divergent methods have brought undeniable results both on and off Japanese soil. Such was his renown that he was offered a place at Hope’s Peak Academy as the Super High-School Level Counter-Terrorist. Even so, the media regularly continues to slander him, claiming that he is such things as the military’s rabid attack dog, a clandestine subversive for hire and a menace to not only Japan but the world at large.

    At the age of seventeen, Rouma was pulled from Hope’s Peak Academy to act as part of a task force cooperating with the United Nations to quell a civil war in the Middle Eastern country of Naryron, a conflict brought on by its venerated young figurehead. While stationed in this foreign land, the young man was placed under the command of Marguerite “Maggie” Rivière, a major in the United States Marine Corps. Although he was initially insubordinate and callous towards his commanding officer, he soon came to admire her upon witnessing her consistently righteous nature and sincere devotion to her platoon – Major Maggie was the ideal of a hero that he once strove to emulate, much like his own parents. Working beneath her had finally allowed Sadao Isayuki to slowly emerge from the ashes of a decade.

    Towards the latter end of his service, Rouma’s platoon received an order to standby at a residential district alongside another squad and await further instructions. Neither he nor Maggie suspected anything of such a directive – much of their spadework up until this point had been either acting as security detail for the country’s figurehead or providing civilians with humanitarian aid. In all likelihood, the extent of their work would involve no more than evacuation or supply distribution... then came the nonchalant order to suppress all non-combatants present in the area for fear of intermingling insurgents – much to their disbelief, deadly force was expressly authorized.

    Although their accompanying squad was quick to leap at the chance to run wild, Rouma refused to allow such a travesty to take place. The first of his fellow soldiers were shot dead before they could so much as lay a hand on the bewildered innocents, inciting the rest to turn their guns on him. Would diverting the bloodshed in this way paint him in a heroic light? Killing one to save a hundred? He certainly thought so at the time. Maggie died defending Rouma in the firefight that ensued – all he had managed to accomplish was slaughter his colleagues, watch his newfound hero perish and pawn his orders off to another group. The reports of the failed operation were later falsified to describe Rouma as the sole survivor of an insurgent ambush.

    With the Naryronian Civil War drawing to a close after almost a year, the young soldier soon returned to Japan decorated with medals of honour from both countries as well as the United Nations... all of which would later be spitefully obliterated at the hands of training mortars. The only tangible remnants of his overseas service were a compounded martyr complex and Maggie’s leavings – a greatcoat riddled with bullet holes and one half of the dog tags that never leave his neck. Constant reminders of the second greatest failure of his life.

    It took a year before Rouma would choose to reenter high school at the ripe age of nineteen, partially due to the incessant fussing of Hope’s Peak Academy’s faculty and scouts.