Around 40 Kenja no Isekai Seikatsu Nikki

Forty-year-old Satoshi Osako is a farmer in the Japanese countryside—and a hardcore player of Swords & Sorceries, an online VRRPG. The day he finally manages to defeat the game's final boss, it curses him with its dying breath and kills him in real life! With a little help from a carefree goddess, Satoshi finds himself reincarnated into a mysterious new world as his in-game character, the incredibly powerful Great Sage known as Zelos Merlin. He accordingly decides to use his newfound powers to...continue living a quiet life on another farm! But first, he'll have to fight his way out of the vast, dangerous forest he woke up in—thanks a lot, goddess—and it won't be long before he's running into bandits, getting roped into teaching a young noble girl magic, and more. Will the almighty Great Sage be able to conquer the toughest quest of all: getting some peace and quiet?

(Source: J-Novel Club)