Enough with This Slow Life! I Was Reincarnated as a High Elf and Now I'm Bored: Volume 5 by rarutori

After finally returning to the center of the continent, Acer’s first and most important visit is to Kaeha’s grave, where he can share with her all the stories of his travels. Her children, grandchildren, and now great-grandchildren carry on her legacy through the Yosogi School. Thanks to Acer’s journey to the Far East, he can bring them the story of Yuzuriha Yosogi and the origin of their school, as well as their lost art of forging katana. He then heads to the home of the high elves in the Forest Depths, which holds the secret to fulfilling his promise to discover the elusive white lake that Airena, Clayas, and Martena had dreamed of. However, Acer is conflicted about returning to his old home after traveling the outside world for nearly a century.