Higaru: My Young Master's Bodyguard Is the Ice-Cold Tachi Girl.

No system + single female protagonist + different world city + daily life Monsters born in another world, demihumans, squeezed into the human world through the cracks. Human existence is threatened and civilization is destroyed. A girl whose parents were killed by monsters - Sakuramiya Rinzuki made a contract with the spirit beast and became the spirit envoy to kill monsters. Such a cute but handsome Taidao girl has become my bodyguard, Jiang Yunling Yichen. But what the world doesn't know is that I, who is regarded as a dandy young master, will soon become the most powerful spiritual messenger in the world. Do you want to live an ordinary life with Lin Yue? Or do you want to become the strongest couple to save the world...