Okiraku Ryoushu no Tanoshii Ryouchi Bouei

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)