Kono Sekai wa Fukanzen Sugiru

Synopsis:

Before dragons invade and she meets Haga, a scholar of everything around him, Nikola is merely a rural girl working at the inn. He belongs to an exclusive group known as "Seeker," which was established to treat a number of illnesses afflicting their generally tranquil society. However, Nikola and Haga both conceal secrets that will alter their entire lives.