Inkyo-gurashi no Ossan, Joou Heika no Tsurugi to Naru

Once a peerless Mechsteel pilot in his youth, Watt Sears is now nearing forty and working as a humble station employee. As a self-proclaimed “old man,” Watt has taken a liking to showing new pilots the ropes, choosing to support them however he can rather than stand in the spotlight himself. Despite the repeated pleas of his boss and the lord of the land to become a Steelrider—one of the elite monster-hunting mech pilots who keep the city safe—Watt is perfectly content with his quiet life. But all of that changes when his storied past catches up to him. Anna, his long-lost daughter from a bygone romance, appears before Watt one day to ask for his help. Resolving to keep her safe, Watt takes Anna under his wing—only to immediately find himself caught up in a not-so-bloodless battle for the throne. With the kingdom in turmoil, can this old knight survive his new post? (Source: J-Novel Club)