Kaoru Mashiko is a first year at Osafune Girl's Academy. Her sword is Nenekirimaru. She is taciturn and does not freely expend energy to trouble herself. She uses the very masculine first-person pronoun "ore." Even though she is short she is a power fighter who can wield a huge sword. She is accompanied by her guardian beast Nene, an aratama. She acts annoyed by Ellen but actually puts a lot of trust in her.