Botsuraku Yotei no Kizoku dakedo, Hima Datta kara Mahou wo Kiwamete mita @COMIC

A man who once lived as a middle-aged commoner drinking beer at a tavern wakes up as Liam Hamilton, the youngest son of a noble count. Confused by his sudden change in status, he recognizes an opportunity to pursue his lifelong dream of learning magic. However, the noble family he now belongs to is on the brink of ruin and must prove its worth to remain in high society. Liam discovers he has a natural talent for magic and seeks to use it to save his family from downfall. Whether he succeeds or ends up back as a commoner remains uncertain.