Heavy is the head that wears the "main character" title. Being the protagonist of a series comes with a lot of responsibility and heavy lifting in anime, and especially so in shonen anime. Not only is a protagonist in charge of carrying large parts of the story, but they're also usually one of the first faces that the audience gets acquainted with. Theirs is the story that is supposed to be the main anchor for the rest of the series and keep everything grounded in one goal. Luffy wants to be King of the Pirates, Naruto wants to be the Hokage—and Midoriya wants to be a hero.
Source：https://www.cbr.com/my-hero-academia-main-characters-explained/
