Erutis

A young Swordsmaster and former mercenary who originally came to kill the "fearsome demon lord," only to find Raenef. Not believing that such a naive, innocent boy could be an evil demon lord, she tried to leave, only to be attacked by a somewhat miffed Raenef. Though she easily beats him in a fight, when she tried to kill him, her sword broke, leaving her with no weapon. Thinking quickly, she managed to trick Raenef into thinking that she would work as a henchman for him. Her intentions were to slip away once he fell asleep. Unfortunately, she ran into Eclipse, who trapped her in a bubble shield and later coerces her into really becoming a servant. Her ambiguous gender becomes a running joke throughout the series (in a character omake, she is seen kicking the artist and writer for deliberately making her seem so boyish). Despite her role as comic relief for most of the series, she is quite skilled as a warrior, with an enchanted blade (which unfortunately broke when Raenef defended himself), replaced with a handmade wooden sword that she is able to use almost as well because of her abilities as a Swordsmaster. To her dismay, her fearsome temper only attracts the attentions of the eccentric Demon Lord Krayon, who insists on following her around and quite inadvertently gets her a position as the head of her own mercenary group. (Source: Wikipedia)