This is a book where dragon mating season comes round again every dragon slayer has felt the pain before but not as bad as this time...

After being cruelly rejected by his friends when they find out he is the son of Satan, Rin Okumura has a talk with Mephisto and decides to leave everyone he knows behind. Two years later, the students of the cram school run across him again, and are unsure about how to deal with the person he has become.