The main guy is Lee Chul, who's basically the embodiment of 'born unlucky'—everything from tripping over air to getting scammed is a normal Tuesday for him. But that's the whole hook; watching him navigate a world seemingly designed to make him fail is weirdly compelling. There's also the female lead, Yoo Ha-rin, a successful prosecutor who gets tangled up with him. She starts off as this straight-laced, by-the-book type who's utterly baffled by his existence, but their dynamic is the engine of the story.
Honestly, the supporting cast is where it gets fun for me. There's his best friend, Jong-su, who's kind of a lovable idiot but fiercely loyal, and then various antagonists who aren't just one-dimensional bullies but often have their own messed-up reasons for targeting Chul. The characters feel like they have lives outside of just reacting to the protagonist's misfortune.
I keep reading because even though Chul is a 'loser,' he's not pathetic. There's a stubborn resilience there that makes you root for him, and seeing how his sheer, chaotic bad luck inadvertently affects everyone around him creates some genuinely hilarious and sometimes surprisingly tense moments. The art does a great job of selling the physical comedy too.