Why is one of Todoroki's eyes blue? Todoroki was burnt when he was a kid, so that explains the scar and what half of his face looks like, but what about the eye? Why is one of his eyes blue and the other grey? Is that a birth condition or is he supposed to be half blind due to the burning or something? (I understand some blind people have white eyes, but maybe the Japanese wanted to represent him being half blind with a blue eye?)
This is rather straighforward. As his father married his mother so that their children have a super-quirk, Shoto inherits his left, fire side from his father (who has blue eyes), and his right side from his mother, who has darker, greyish eyes.