Toshinori Yagi, famously known as All Might, was the No.1 Superhero in the world. He was also formerly known as the Symbol of Peace. He had a quirk called One-For-All, which allowed him to gain superhuman strength, speed, durability and stamina. He received this quirk from a former hero named Nana Shimura. After All Might defeated All-For-One, he retired as the greatest hero due to losing his quirk. He passed on One For All to Izuku Midoriya and is currently helping him to become the greatest hero on earth.