This story takes place about one hundred years ago. Nadja is a bright, cheerful girl who was raised in an orphanage near London, England. Nadja was entrusted to the orphanage when she was a baby. So she thought her father and mother were dead. But before her thirteenth birthday, she found out that her mother might be alive.. Nadja sets out on a journey to find her mother! With all of Europe as the stage, Nadja's exciting adventure begins!

Venturing into the wilderness, the skeptical Ryouta Murakami and the ambitious Kuroneko were on a quest to prove the existence of extraterrestrial life when a tragic accident occurred, reaping Kuroneko of her life and leaving Ryouta in a critically injured state. Ten years have passed since the disaster, and Ryouta is now living a normal life in high school. He vows to prove that aliens are real in honor of his late friend. A transfer student named Neko Kuroha unexpectedly arrives one day, bearing a striking resemblance to the late Kuroneko—even sharing a similar name. Most mysteriously, she seems to possess supernatural powers. As Ryouta takes more interest in Neko, he is drawn into a deadly world where dangerous scientists hunt magic-wielding witches that have escaped from their secret research laboratory. Neko is one of these escapees, but there are many others who are in similar situations, and it's up to Ryouta to protect them from their would-be captors.

Lu Fan, a white-collar urban woman who has always considered herself a more ordinary woman than anyone else, is suddenly abducted by an alien one day. The alien, who claim to be from Saturn, tells the absurd reason for their invasion of Earth, and that the key to the invasion plan is to make Lu Fan fall in love with him and then betray the Earth. In the funny daily life with the Saturnian, aliens from various planets start to appear around Lu Fan one after another! These aliens have their own objectives, but because of their intertwined destinies, they all end up in Beijing. Lu Fan begins to realize that she is not as ordinary as she thought, and she slowly develops a crush on the Saturnian. How will she choose?

Sonnet is a cyborg/esper from a harsh background and now trained to be the ultimate warrior and most powerful weapon in the world. She is sent to Japan to watch Komatsuzaki Lan, who is thought to be controlled by the rage of the esper Akai Kiba (Crimson Fang). Lan is a quiet girl who knows she's different from everybody else and starts to show signs of Crimson Fang after coming into contact with Sonnet. In the course of fighting with Lan, Sonnet starts to rediscover her humanity. At the same time Lan has to fight to retain her humanity and control the Crimson Fang.