Nobita
Nobita's basically the heart of Doraemon, even though—or maybe because—he's a mess. He's a fourth grader living in Tokyo as an only child, and he's got every underdog trait you can think of: terrible at school, hopeless at sports, cosmically unlucky, and about as remarkable-looking as beige wallpaper. His laziness is legendary.
What makes him work as a protagonist is that he actually tries to be better, even when the odds (and Doraemon's gadgets) inevitably backfire on him. Those constant failures and his stubborn attempts to overcome them are basically what the whole series runs on. He's not winning any medals or acing any tests, but he keeps showing up and fumbling through it anyway, which somehow makes him weirdly relatable.
Content compiled by AnimeList.moe from publicly available sources.