The Apartment I Rented Is Also A Gateway To Another World!

Full name: The Apartment I Rented Is Also A Gateway To Another World, But I Can Not Pass Through It! Hakaku Koyama a 19 year old teen on leap year before his first year of college rents a cheap apartment to lower costs. He soon finds out that the mirror in his hallway is a gateway to another world. Out of it comes the demon girl - Damaru Yakushtazushakata. Wanting to go back Damayo tries to go back through the portal, but finds out she's stuck in the human world and has to live with Hakaku doing normal human activities.