『Zero』

The title character. She is a witch, child-like in appearance, but presumably much older. She is proficient in both sorcery and magic, having created the latter by writing her very own spellbook called the"Grimoire of Zero". Despite her immense knowledge, she is clueless with regards to basic knowledge, such as the value of gems and monetary transactions. Situations that may normally embarrass others, hold no problem for her. She employed the Mercenary, after promising to grant him his true human form. Zero has shown an interest in growing closer to him as the series progresses. At the end of the novel series, the two of them marry and open their own tavern in his home village. She also seems to prefer the comfort of Mercenary's stomach fur to that of a real bed. She is the younger sister of Thirteen.