
To defeat him, he decides that since heroes are the ones who are able to defeat Overlords, he needs to become a hero to be able to defeat his father. His goal in life is to defeat his father, the Overlord.

Mao is the #1 Honor Student and son of the chairman at Evil Academy. Spoiler warning: Plot and/or ending details follow. As the story goes on, he slowly turns towards good, and considers the other people around to be friends, but never admits it. When Mao stole Almaz's "Hero" title, it began slowly manifesting within him causing his speech to become more normal and "human like". Mao's hatred of his father hides the respect he truly has for him deep down, similarly to Laharl (this is noted in the Netherbattle Tournament in Disgaea 4). He believed that by learning about them, he can find a method to overthrow his father and take the title of Overlord for himself.

Despite his hatred for humans and heroes, he continually studies them, even keeping an observation journal to record his data. He is willing to do whatever it takes to defeat his father, even if it seems stupid or is something he hates to do. This tendency and the bizarre nature of his research has caused many to label him as a creep and total pervert which he hopelessly protests. Whenever he finds a subject for experimentation his glasses fog over as he starts breathing heavily and drooling, a habit that tends to disturb the "subject" and other people around him. With his high Evil Quotient, he loves experimenting and studying subjects to gain new information from whatever he finds interesting. Mao apparently has an "Evil Quotient" of 1.8 million, which he is especially proud of. He keeps more secrets in his Heart Bank than any other demon in the Netherworld Academy, making him the #1 Honor Student. His blatant disregard of rules earned him the spot of #1 Student in the Academy as he has not once shown up in class, nor has he ever participated in any school activities, such as homework or volunteering. Mao is a typical Demon: he does not care about the problems of others, will often take what he wants, and uses force to rule over others. When Mao is excited or intruiged by something, his glasses will fog up and appear totally white, which is a common trope for characters with glasses in anime. His eyes typically appear to be angry, and his resting facial position tends to be a scowl. The bottoms of his shoes are black, and he has one gold button on each side of his shoes' exaggeratedly wide tops, coming to four in total. He has black socks and wears large, cartoony red shoes that resemble high-topped basketball shoes with black shoelaces and some white patterning.

He has a black colored belt with a golden, typical-looking belt buckle. Mao wears black dress shorts underneath white shorts that flare exaggeratedly wide towards their openings for his legs. The inside of the jacket is colored magenta, and the popped collar has small, rectangular golden studs near the front. The ends of the jacket's sleeves are black with a black pattern just above the ends, made up of a large centered circle and a rectangular band around the rest of the way. His jacket is red with 4 golden buttons on each side of its front opening, and is linked together near the collar by silver chains. His shirt is black and long-sleeved, with four golden buttons arranged 2 by 2 at the end of each of them. Mao's outfit resembles that of a school uniform, with his jacket being worn more like a cape than what it actually is. Mao is a demon with pale skin, red eyes, pointy ears, round glasses, and incredibly scruffy white hair.
