崖っぷち貴族の生き残り戦略, Survival Strategies of a Struggling Aristocrat,

In the other world, he uses knowledge from Earth as a weapon! On Earth, he uses magic from the other world! A fantasy epic about rising to power in two worlds, sharing the soul! One day, Dennis, the second son of a poor lord, realizes that he is sharing consciousness with Masaya, a middle-aged man from another world. Though he is confused, Dennis thinks that Masaya's knowledge could help restore the economy of the territory, and so he sets out to save his family and the people...!