SSS-Rank Ace: Codename Death

Carter, a top operative known as the Crimson Reaper, comes home after three years abroad and meets Chloe, who doubts him because of his ordinary appearance. He wins her over fast with his fighting skill, then accepts a job guarding Chloe's defense patent from the Obsidian Syndicate while looking out for his sister Lily. Along the way he deals with bullies, outmaneuvers the rival boyfriend of his ex, and tangles with ruthless mercenaries and hidden enemies inside the company.