Easygoing Territory Defense by the Optimistic Lord

Okiraku Ryoushu no Tanoshii Ryouchi Bouei: Seisan-kei Majutsu de Na mo na Kimura wo Saikyou no Jousai Toshi ni · お気楽領主の楽しい領地防衛～生産系魔術で名もなき村を最強の城塞都市に～

Van, the fourth son of a powerful noble, is only two years old when he remembers his past life as a salaryman in Japan. With his adult brain in a young body, he's considered a child prodigy...until he displays the "Production Magic" skill when he turns eight. In a family that favors offensive magic, this crafting skill is considered useless in battle, and Van is banished to oversee a tiny country town in disgrace. With only his personal maid, the memories of his past life, and his "worthless" magic, can Van improve the fortunes of this little village—and himself? (Source: Seven Seas Entertainment)