Jin was your average human being. He just has the ability to summon demons for some reason. Which is okay, as the demons he knows are quite nice and love his cooking. In return for dinner, they keep his apartment mouse free, which is a good deal in his opinion. If he one day accidentally summons one of the Princes of the Underworld, one of the Seven Sins, no one has to know...  

Jin locked his door every night before he went to bed because of a certain roommate.