Mai is a well-endowed girl with purple hair and green eyes. She has her hair folded upwards and tied into place with a pink ribbon. Mai typically wears the uniform of Minoseki Academy, but also uses a frilly petticoat under her skirt.
She possesses an older-sister like tendency to take care of others. She is also quite calm and brave, willing to fight for those she care about and what she believe in and is a hardworking person who never hesitates in the face of hardships, but somewhat shy and reserved as well. She makes confectioneries as a hobby, and is particularly proud about the cookies she makes.
She stands as the poster girl of the emerging company Yanase Group, and has two younger sisters named Miu and Shiori. She is currently an honor student in Minoseki. She joined Minoseki Academy in middle grade, meeting Kanami and become her friend at some point before the series start.
After completing the academic and practical exams for the school term, Mai participated in the Minoseki Academy Representative Selection Tournament, ultimately losing to her friend Kanami Etou in the decisive match. Despite this, she and Kanami would represent the school in the National Swordsmanship Tournament. Although happy to join the tournament with Kanami, Mai was worried that she would be unable to manifest Utsushi during the matches.
In the Origami Mansion in Kamakura City, Mai demonstrated her prowess by defeating Kaoru Mashiko of Osafune Girls' Academy. However, she was matched against Kanami once more, and despite her attempt to use iai against Kanami, Mai would lose as Kanami caught her hand before she could land a blow. Mai would later join the other spectating students of The Five Traditions on the decisive match between Kanami and Heijou Institute's Hiyori Juujou, and she eventually became one of the many witnesses of Hiyori's attack on Yukari Origami and the ensuing escape by the attacker and Kanami.
As Kanami's companion in the tournament, Mai was interrogated by one of the Origami Family's Elite Guard, Maki Shidou, and she was released after proving her lack of knowledge about Kanami's actions. However, due to her concern for Kanami, she chose to find ways to look for Kanami and Hiyori, both of which have reached Tokyo several hours later. Mai used her connections from the Yanase Group to organize a search for the two fugitives, only to fail in finding them in time. Mai would eventually find them confronting an Aradama. Although Mai initially demanded Hiyori's custody in favor of softer punishments for Kanami, neither would yield to Mai's request with both of them revealing "something unusual" about Yukari's identity. Because of her trust in Kanami, Mai decided to set them free and report her failure in returning with the fugitives, something that was met with disappointment from Yukina Takatsu, the president of Renpu Girls' School.
Master Swordsmanship: Mai is extremely skilled in kenjutsu, enough to make her the runner-up of Minoseki Academy and representative the said academy, make her way into the semi-final of National Swordsmanship Tournament. She even outclassed Hiyori Juujou, another skilled Toji who make her way into the final match National Swordsmanship Tournament, in brief exchange of blow.
- Swordsmanship Style: Hokushin Itto-Ryu (北辰一刀流?) - A style that takes away the illogical parts of swordsmanship techniques in a process symbolized by the founder of the style in the words, "Wielding a sword is as quick as a dance; the heart and mind must act as one", leaving a system of organized and easy to learn techniques. This style was later used as a basis for modern-day kendo techniques.
Keen Intellect: She is quite smart, capable of predicting whereabout of people just by hearing surrounding and enviroment sound through phone. Calmly reacting to the situation she face and making decision. She also good at forming decent plan.
Utsushi Proficiency: Mai, like Kanami, is capable of maintaining Utsushi for the longest duration in her class in Minoseki.
Cooking Skill: Being noted by both Kanami and Sayaka that she possess incredible skill at making cookies.
Okatana: Magoroku Kanemoto (孫六兼元?) - An uchigatana by world-famous swordsmith Magoroku Kanemoto. It is said that Magoroku himself made the sword. The sword is tempered using the sanbon-sugi style, which is evident on the blade's hamon.