I'm Not the Hero, Getting Stronger as a Side Character

A white truck led to Bruce's death. Then he was reborn in a world of sword and magic, and he didn't come without a little bit of gift for his previous untimely death. Reborn as Rohan Coltgrove, a member of a minor branch family serving the prestigious House Colt, he finds himself in a world of swords, magic, and nobility. Armed with an RPG-like system and a loving new family, all Rohan wants is a peaceful life and the satisfaction of steadily growing stronger. Unfortunately, fate has other plans. Not only does he keep crossing paths with the Hero—the overpowered protagonist of this world—but disasters also begin threatening the people he cares about. To protect his family, secure his future, and wipe that infuriating smirk off the Hero's face, Rohan has no choice but to grow stronger. After all, surviving as a side character is a lot harder than it sounds.