Toshinori Yagi, alias All Might, rose from a Quirkless existence in a superpowered society to become its greatest protector. Chosen by Nana Shimura, the seventh holder of the transmissible Quirk One For All, he honed his abilities under mentor Gran Torino. When All For One murdered Nana, Toshinori channeled his grief into forging a heroic identity abroad, adopting American-inspired combat techniques like Detroit Smash and a vibrant red, white, and blue costume. His U.S. tenure included partnering with inventor David Shield, who crafted specialized gear to augment his crime-fighting efforts. As One For All’s eighth wielder, All Might emerged as Japan’s Symbol of Peace, slashing national crime rates to 3% through sheer power and magnetic charisma. His muscular hero form masked a gaunt, injury-ravaged body—a consequence of All For One shattering his respiratory system and stomach. For years, he hid this frailty to preserve public hope, even as his heroic stamina dwindled to brief daily windows. Retiring after depleting One For All’s embers in a climactic clash with All For One, he shifted to instructing Foundational Hero Studies at U.A. High. Mentoring successor Izuku Midoriya, he emphasized moral integrity alongside physical training, though his teaching initially faltered from underestimating the struggles of innate Quirk users—a blind spot born of his own seamless mastery. Beneath his jovial demeanor and trademark reassuring smile, taught by Nana, lay a man burdened by guilt and the weight of societal expectation. This duality shaped his alliances: he valued Sir Nighteye’s partnership yet rejected rigid succession plans, championing Izuku’s innate heroism over calculated destiny. During the Final War, All Might fought alongside new heroes in a Quirk-replicating armored suit, sacrificing the gear and nearly his legs to stall All For One. Though temporarily wheelchair-bound post-battle, he regained mobility and pivoted to advocating systemic hero reforms. His legacy persisted through proteges like Izuku and even the reformed villain Stain, who revered his unyielding ideals. Stripped of One For All yet undeterred, Toshinori endured as a beacon of hope, proving that heroism transcends power—a testament to resilience in an era redefining what it means to save others.