The protagonists in Fire Force experience enough of sorrow in their lives since they live in a world where Infernals created from spontaneous human combustion inflict a lot of death and damage. While most of the disasters they go through are brought on by the White Clad and the Evangelist's bad deeds, occasionally calamities happen for no reason at all. This is perfectly shown by the backstory of the deuteragonist Arthur Boyle.
The start of Arthur's journey to becoming the strong-willed, dim-witted, self-proclaimed knight that fans know and love began early on in his childhood. During the second episode of Enen no Shouboutai: Ni no Shou (Fire Force Season 2), Arthur's backstory is revealed in a tragic flashback. The episode, titled "Flames of Madness," provides context to the source of his power, which viewers learn is connected to his deep psychological and emotional trauma.
Raised by his mother and father in a financially unstable home, Arthur lived a modest life with his parents, whose income relied solely on the success of their family-owned eatery. One day, the Boyle family's restaurant went up in flames, leaving the establishment destroyed. News of the café burning down reached media outlets, and it wasn't long until speculations regarding the reasoning behind the fire were tied to customers' complaints of food poisoning.
Young Arthur told his mother he was worried about the future of their business after seeing the news program on television. She disregarded his question and told him to go get his father so they could have dinner. In the next room, Arthur found his father asleep with his face covered by a hat. In response to Arthur's persistent concerns about their financial situation, his father ignored him. Arthur then expressed interest in learning more about the contents of the cowboy-style hat that his father had found so intriguing. Taking advantage of the chance to divert his son's attention, his father jokedly persuaded him to look inside the hat, saying it held the entirety of the cosmos.. With his vision gone dark, Arthur's creative mind took over as he imagined his family as royalty, living in a beautiful castle, surrounded by luxury and nobility.
The following morning, Arthur woke up to find his parents gone and a note left behind to explain their absence. The letter read: "To our dear son, Arthur, Your mother and father have gone on a journey to save the world! The castle is all yours!! As of today, you are the king!!!"
After being unexpectedly left alone, Arthur uses his innocent imagination to picture a better existence, a coping mechanism his father purposefully put in him to make up for their negligence. Without someone to help him, Arthur relies on his parents' parting words and makes the most of a bad situation. He continues to rely on his dreams to create an identity for himself and get away from his unpleasant reality. Arthur, who is blissfully oblivious of his parents' use of deception to cover up their desertion, draws strength from his horrific experiences. Because of this, a lot of fans concur that Arthur's history is by far the most tragic in the series.