A poor high school boy, Izuki Tomonari, got caught up in a kidnapping attempt on Hinako Konohana, a young lady from one of Japan's largest conglomerates. On the surface, Hinako appears to be a brilliant and beautiful young woman, but in reality, she is a lazy girl with no life skills. However, due to family reasons, Hinako has to play the role of the "perfect young lady" at school. Wanting to protect her, Izuki took on the job of caring for her. Eventually, Hinako began to spoil Izuki with all her might. "I don't want... Izuki to leave my side right now." This is a love story that begins beyond the master-servant relationship featuring a princess with a beautiful facade.

Young Sain Forth has it made; as the famed Holy Knight, he has the people’s love, the respect of kings, and the blessings of a literal goddess. His aspirations lie elsewhere, though. With his assistant Melia at his side, he leaves for an academy in a foreign kingdom, where he is treated as a deviant by his peers. It’s his own fault, mind you—his stubborn insistance on wearing a custom, all-black uniform makes him stick out. He isn’t the only outcast in his class: Alicia, born into the Clan of Light but unable to use anything but fire magic, faces similar struggles, and the two quickly become allies. Alicia proposes that they enter the labyrinth below the school in search of a holy sword, but Sain has other plans in mind: a doom sword. And so, with his friends in tow, Sain ventures into the perilous unknown, driven by a wish to become the coolest, edgiest, most awesome thing in existence: a Dark Knight. There’s just one problem. He can’t use dark magic. Like, at all.