Ellen is a well-endowed girl with long straight blonde hair and bluish-purple eyes. She is often seen with Osafune Girls' Academy uniform with black high-heeled Mary Janes and asymmetrical white stockings. She also wears a black headband.
She tends to be the moodmaker, having a simplistic personality and has a smile on her face all the time; has a good relationship with Kaoru as a partner. She immediately acts friendly to people she meets, and has a tendency to make up nicknames for anyone she meets in combat.
Despite that, she is clever and brave, willingly risking her life to protect her comrades.
She is half-Japanese, with a Japanese father (Kimitaka Kohagura) and an American mother (Jacqueline Anne Kohagura). Her grandfather, Richard Friedman, was the pioneer in developing S-Equipment. She joined Osafune Girls' Academy, meeting Kaoru and becoming her friend at some point before the series' start.
She participated in the National Swordsmanship Tournament along with Kaoru as Osafune Girls' Academy's representative, but lost to Hiyori Juujou.
Expert Swordsmanship: She proved to be well-versed in kenjutsu, being able to hold her own against Hiyori, another skilled Toji.
- Swordsmanship Style: Taisha-Ryu (タイ捨流?) - a swordsmanship style known for its energetic movements consisting of hopping and spinning one's body, a style that deviates from other traditional ones. This style adopts kenpo techniques from Mainland China, but with the addition of thrusting strikes and kicks.
Expert Hand-to-Hand Combat: She also is very good at hand-to-hand combat, easily overwhelming Yomi when she combined her sword skill with punches and kicks.
Immense Durability: Very skilled in using Kongoushi, which in tandem with Toji's power provides her with strong physical defense.
Immense Stamina: She is shown to have a good amount of stamina, capable of fighting for a long time using Utsushi.
Keen Intellect: She is quite smart, capable of noticing small details of her surrounding and situations she is in; capable of forming a decent plan, doing infiltration, acting and hiding her true intentions from Suzuka, a tactical expert of Origami Family's Elite Guard. As a granddaughter of Friedman she has very good knowledge of Noro technology.
Utsushi Proficiency: She is capable of maintaining Utsushi for a very long time, and reactivating it multiple times during her fight with Yomi. She is even capable of maintaining it while enduring numerous slashes.
Okatana: Echizen Yasutsugu (越前康継?) - an uchigatana crafted by Yasutsugu Echizen, a swordsmith that had worked under the Tokugawa shogunate. At the beginning, a large amount of Yasutsugu's swords were composed of "namban-tetsu", a kind of steel imported from Europe.
Knife: She is shown to have a knife hidden inside the heel of one of her shoes.
- Her nicknames for the girls she met: Mai = Maimai, Kanami = Kanamin, Hiyori = Hiyoyon, Sayaka = Saaya.