Leicester Maycraft, a renowned item engineer and swordsman of the adventurer guild Oasis in Ert'Aria, wields expertise in manipulating Ale, the mystical energy fueling his inventive repairs and upgrades. His ingenuity shines in creations like a hedge trimmer fused with a beam shooter or hybrid blade-firearms, earning him constant demand within the trading city. Though surrounded by chaos, his calm patience anchors his companions, tempering their conflicts with steady diplomacy.

While harvesting Ale during a meteor shower, Leicester unearths Minette, an automaton who instantly claims him as her father. Embracing this role, he shields her with unwavering devotion, their bond rooted in his father Nagan’s past ties to her creator, Mise Altoise. This connection weaves his lineage into Ert'Aria’s automaton history, deepening his resolve to protect synthetic and human lives alike.

Raised by Shelley Maycraft—a mother often misjudged as his sister due to her youthful warmth—and Nagan, linked to the city’s infrastructure, Leicester shares a complex history with childhood friend Carina Verritti. The mage and ruler’s daughter nurses unspoken affection for him, which he gently sidesteps without rejection. His reliability extends to allies like Agnes Boulange, whose puppeteering quirks he navigates, and Chelsea Arcot, the directionally challenged knight whose misadventures he rectifies, cementing his reputation as Oasis’s steadfast problem-solver.

Consistently portrayed as a selfless leader across adaptations, Leicester prioritizes mediation and collective survival. The visual novel delves into his nuanced relationships through branching storylines, while the anime highlights his strategic unity during crises like the Heaven’s Waterwheel threat. Regardless of format, his moral compass remains unshaken: he advocates mercy for foes like Aberdeen Roland and Avril, balancing Ert'Aria’s magical and social equilibrium through combat skill, diplomacy, and Ale-driven innovation.