Itai-San is a middle school student who loves dark magic. She says she's 100,000 years old, but she's actually 14.
She is extremely childish (No shock there), and has chuunibyou-like expressionisms (term typically used to describe early teens who have grandiose delusions, who desperately want to stand out, and who have convinced themselves that they have hidden knowledge or secret powers). She often takes up the role of the protagonist, becoming a narrator of her own life or the actions of others around her. She does whatever seems the most fun at the moment, or what will cause the biggest scene that will get her the most attention.
But despite her interactions with the strange incidents in Nijiura Town, among gods, demons, monsters, robots, and other supernatural beings, she often faints and does not remember any of them actually happening to her. This makes her believe that a lot of the events in the town were a part of her vibrant imagination.
Otherwise, she is very oblivious to the strange happenings around her especially with particular individuals she interacts with. (She would over-rationalize her situations. For example, 3M would just be a very tall lady to her.)
She attends Megaku (The school for the maids) as a junior high student, and is a central figure within her school due to her expressionate behavior. She tends to study dark history and black magic, in order to practice her skillsets.
She isn't a very good maid due to her young age and ignorance in housekeeping, but she is very good at arts and crafts. She enjoys creating and decorating replica weaponry.
She carries around a dark history notebook that she uses to recite her spells. Though, it only does menial things such as making somebody's stomach hurt.
She is mortal enemies with Fanshii-San (Fancy-San), who stalks her, thinking Itai to be a soulmate from a previous life. Whenever they meet, they always battle.
Itai is often treated like a younger sister by everybody in Nijiura Town.
She has authentic white hair due to her Germanic heritage from her grandmother, but her heterochromatic eyes are done by contact lenses.