Volume 2 is now available from KADOKAWA BOOKS (the plot differs slightly from the web version).

https://syosetu.com/syuppan/view/bookid/4202/

Souya, 37, a section chief at a trading company in a regional city, is a salaryman who revels in his single life. One day, he awakens in an unfamiliar grassland, witnesses twin moons floating in the night sky, and regains memories of being transported to another world twenty years ago. This is an otherworld adventure story about a middle-aged man in a business suit—low on enthusiasm, high on ability, cool yet a little hapless. While it's an isekai story, it might also contain a blend of classic fantasy atmosphere.

Note: Also available on Kakuyomu.

Full text revision in progress. Revision progress: 19/127 chapters.