Height 186cm. He transferred in as a high school sophomore, but his actual age is unknown. Quadrius has a playful and easygoing personality. He loves having fun and has a lot of nerve, possessing the initiative to jump into things he wants to do without regard for danger. While he seems like he isn't thinking about anything, he observes his surroundings more than anyone else and cares for others. He is kind, funny, and smart. His favorite subject is science. However, he is bad at memorizing things and is somewhat forgetful. He has a mushroom haircut. His green hair is actually his natural color, not dyed. He says his piercings are a family policy. He apparently has two older brothers and two older sisters. When asked about his parents, he replies, "Well, my big sister is basically like my mom." In reality, he is a semi-artificial human. Quadrius's sister is a witch who kidnapped a human on a whim to create him. Therefore, the people he calls his brothers and sisters are not his biological siblings. Because he is semi-artificial, he is unharmed no matter what height he falls from. However, his body doesn't mend itself on the spot; he has to return to his witch sister to have his body repaired. Even if his heart is lost, he has spares, so he can be revived if he returns home. He shares his vision with his sister, who acts as his mother figure. She ordered him to "go blend in with the students because I want to see what human life is like." Quadrius lives according to that command. Consequently, if their family's true identity is ever close to being exposed, they erase the memories of everyone involved and move to another city. They have repeated this lifestyle many times. Though he has a bright personality, there is a part of him that looks down on humans as inferior beings.