I'LL SET MY HEART ABLAZE

Rengoku and Izuku were brothers as Izuku always looked up to his Older brother who was a Hero/Demon Slayer and he inspired Izuku as he wanted to be a hero like him however one day Rengoku is killed by a Villain saddening Izuku and from that day on his Mom and Dad Inko & Shinjuro ignored Izuku because of his Brother's death and because of this Izuku starts to train like his brother training to be a Hero like his Big Brother and make him proud and to Avenge his brother if given the opportunity