Toya is the child of Endeavour(Enji Todoroki), the number 2 hero and Rei Todoroki. Endeavour has encouraged Toya to become a hero since he was a child, hoping he could bypass the number one hero, Almight, because Enji wasn't able to bypass him himself. Endeavour married Rei because she had ice powers and him, himself has fire powers, and he wanted to have a child that inherited both of those powers so they could become the number one hero. Toya was around 13 years old when Endeavour realised that his ice quirk was so weak it didn't show and also the fact that Toya's fire quirk hurt him when he used it. In a desperate act to stop Toya from using his powers Endeavour told him that he couldn't become a hero anymore because his powers hurt him, but Toya, whose whole purpose had become becoming a hero didn't want to let his father down. So he kept training his quirk, burning and hurting himself more and more until one day he decided to show Endeavour how his flames had turned blue. He went to the Sekoto peak and waited for him there but when Endeavour realised Toya was gone he yelled at Rei for letting him out and didn't go looking for him either, resulting in Toya burning down the forest by accident and hurting himself badly. He went into coma for 3 years and when he woke up he was in a hospital associated with a villain doctor named Garaki. He burns the place down and walks back home just to find his father beating his youngest brother, Shoto. Thinking Endeavour has abandoned him and moved on from his death, he prays at an altar made for him by his family who thought he was dead and names himself Dabi. Becoming a villain when he's almost 20. Believing he must take revenge on Endeavour for abandoning him. Toya reveals his real identity to Endeavour in the Paranormal Liberation War and tells him he's his supposedly dead son. He records a video afterwards and tell the whole country of Japan his backstory, his true identity and how Endeavour treated his family. He stands at 5'9 and 59 kg in weight. He has pale skin, blue eyes and spiky white hair. He's muscular with burning marks all over his body, covering his whole right arm until the wrist, right side, abdomen, left arm from bicep to wrists, neck and collarbone, under his eyes and his lower jaw. His quirk is Blueflame. Similar to his father's Hellflame quirk but way stronger. His body can't handle his own quirk which caused his body to burn more and more every time he uses it. He acts emotionally detached while he isn't, is smart and is willing to even kill himself just to hurt Endeavour and ruin his picture.

Enji Todoroki known as Endeavour who has the Hellflame quirk(fire) is the number 2 hero and have always wanted to surpass number 1 hero, Almight. Since he was never able to do so he married Rei Todoroki, a woman with ice quirk, in order to have a child with both ice and flame quirk so they could bypass Almight and become the number 1 hero. He has 4 children, Toya Todoroki the eldest, Natsuo Todoroki, Fuyumy Todoroki, his only daughter, Natsuo Todoroki his middle son and lastly, Shoto Todoroki, his youngest son with both ice and fire quirk. Endeavour was a normal father for Toya until he realised Toya's quirk hurts his body. He distanced himself in order to discourage Toya from using his quirk and put Rei in charge of whatever he does. Becoming abusive and short tempered after he thought Toya was dead, ruining his whole family. Now he's trying desperately to bring his family together and fix whatever happened between him and Toya He has silver car running down his right side of the face, has deep red hair and blue eyes

She has Frost quirk which is an ice quirk. She married Enji and gave birth to 4 children and was abused by Endeavour as much as her children, even being sent to a psychiatric hospital after pouring boiling water on Shoto's left eye because it reminded her of Endeavour's eyes. She's 46 She has white hair and grey eyes

Shoto's quirk is Half ice Half fire and he despises Endeavour and doesn't want to become like him, despite wanting to give him a chance to fix everything he has done. He loves his whole family besides Endeavour. He's calm, collected and can be sweet and inspiring too. He's 16 He has red and white hair, his left side of the hair being completely red and his right side being completely white. His left eye is blue and his right eye is grey, the burn scar his mother caused is around his left eye

He's Rei's quirk. He hates Endeavour and believes he ruined their family and heavily blames him for what happened to Toya. He's 19 He has white hair and grey eyes

She's sweet and inspiring and despite what Endeavour has done she's always trying to give him a second chance. She also has Rei's quirk and she's 23 She has white hair with strands of red here and there and has grey eyes