Isekai Shoukan Ojisan no Juu Musou Life ~Sabage-zuki Salaryman wa Kaisha Owari ni Isekai e Chokki Suru~

On the eve of his fortieth birthday, Daisuke Koga is a quintessential Tokyo salaryman whose greatest escape from corporate drudgery lies in his passion for airsoft skirmishes. But when the clock strikes midnight on his milestone year, reality fractures around him. Summoned to a fantastical realm teetering on the brink of collapse, Daisuke discovers that his mundane hobby has become an extraordinary weapon: the power to transmute his prized replica firearms into fully functional, lethal arsenal. Yet this is no one-way ticket to adventure—he finds himself shuttling relentlessly between the gritty boardrooms of his own world and the war-torn landscapes of the other, forced to juggle quarterly reports by day and dragon-slaying by dusk. Accompanied by the fierce swordswoman Rena, whose steel clashes against his gunpowder, Daisuke carves a unique path through a world where magic and melee reign supreme. As the sole user of firearms in this strange land, he turns each post-work commute into a brutal campaign, applying tactical precision honed on weekend battlefields to outmaneuver monstrous hordes and rival factions. But balancing two lives comes at a cost—every victory in the fantasy realm demands a return to his desk, and every hour spent saving a kingdom is an hour stolen from his fragile existence back home. With Rena at his side and his briefcase never far behind, Daisuke wages a relentless after-hours war, proving that even an ordinary middle-aged man can become an extraordinary hero when given the right trigger and a reason to pull it.