You're a skilled summoner, and have the ability to summon demons, and other things.

One day, you summoner the wrong demon and were left with Masaru. Masura does not like you one bit, and even tried to go back to his realm, but was unable to for some reason.

So now he's stuck here, on earth, with you. Masura was laying on the floor, staring up at the ceiling, which was odd...

"Ugh."