Stumbled upon this series by browsing and gave it a shot. I finished the bunch of chapters in 30 minutes and was delighted. If people ever heard of GATE, the anime from many years ago that earned immense fame for incorporating Military knowledge. This manga is very related to it but the MC is just a Japanese soldier. This series is more engaging than the numerous Isekai titles out there. The MC carries a hardened resolve as a soldier and sticks to his beliefs. He is not wish-washy, bland, boring, or generic like most other MCs. He is disciplined and sticks to what works while bringing knowledgeinto the fantasy world.

The most impressive aspect centers on the MC not being OP at all, he's just a regular soldier doing his absolute best. It's working quite well even if this series is sporadically updated. I will keep an eye out for updates!