Gate: Jieitai Kanochi nite, Kaku Tatakaeri

The idea of a modern technological society colliding with a magical world is undeniably fascinating, but regrettably the story lacks complexity and coherency when it comes to wordbuilding. Nevertheless, the story may still prove enjoyable to skim through, as long as you don't try to think about it too deeply.

Also since the protagonist is merely a Lieutenant, you should expect a substantial number of events to be of a respective magnitude.

Other than that, characters are quite likable and their interactions are fairly amusing, so if you are in a mood for a naive adventure it might be worth giving a shot.