Eight words describe the feelings of Youtarou Hanabusa: I just want to live a normal life. Unfortunately for him, as a member of the Knights of the World, his training in this ancient and international order has left him with a condition he calls White Knight Syndrome. This condition causes Youtarou to instinctively act heroically and chivalrously whenever he encounters someone in danger. To protect his identity in such embarrassing moments, he carries a mask with him at all times. Then one day, he saves the life of Makio Kidouin, the young daughter of an elite and affluent family. Little does he know that this singular act of heroism will change his life forever. Soon, he is simultaneously blessed with a life in the lap of luxury and cursed with one of abnormality, for his new friend Makio lives a life far removed from the everyday. Between coping with the hijinks of six-year-old Makio, and dealing with a cast of odd friends and scheming enemies, Youtarou must protect his new friend while keeping his identity hidden as the masked hero Knight Lancer.

It is the early 21st century, and mankind is doomed. Due to a mysterious virus that steals the essence of human life, humanity has been pushed to the brink of extinction with only one hope for salvation: the blood of a vampire. Vampires have closely guarded the key to curing the virus for several years, which has led to an immense rift between them and humans and the world's descension into chaos. A vampire named Duo, having leaked the secret to saving humanity, is now considered a traitor to his race, and the powerful vampire Zieg is on his trail. However, due to Zieg's sense of duty, his heart is torn: should he kill the man who betrayed his people, or will his personal history with Duo sway him to have a change of heart?

In a small village, twins are born: a boy, Tatara, and a girl, Sarasa. The prophet Nagi declares that Tatara is the chosen one who will free Japan from the tyrannical rule of the King and his four sons. But when the ruthless Red King slays Tatara, Sarasa must take on her brother's name and responsibilities and embark on a quest to free Japan and deliver vengeance to the Red King. (Source: ANN)

The story continues after the intraschool music competition of the first game and anime series. The budding music student Kahoko meets the brusque boy Etō, the new youthful school board director Akihiko Kira, and the mysterious transfer student Aoi Kaji. (Source: ANN)