Gate: Jieitai Kanochi nite, Kaku Tatakaeri, Cop Craft Recommendations
In both shows, a portal opens and connects two diffrend worlds a fantasy and a modern one. The shows involve a millitary/police guy and girl(s) from the fantasy world where they work together fixing problems along the way.
Somewhere in the world a gate has opened linking modern day Earth with fantasy world.
Two main characters are also the same - a man with military experience and badass loli.
Both have that same plot where it involves a portal from an alternate world of magic and supernatural opens up in public where humans from earth had assimilated with each other.