Aflame Inferno

Aflame Inferno is about a self absorbed high schooler, Kang Shichan, that gets caught in the middle of a battle between demons. Injured severely and near death, the demon Inferno merges with the student to save his life. Together they win the battle to discover that they are inescapably joined. The only hope of ever being separate beings is to close down 1,000 Invento Hells and find the right spell of Resurrection. Can Kang Shichan balance hunting down demons with his school work?
Note: The series changes from Korean to Japanese. Name and location switch with the publications nationality around chapter 43.