Yume is a girl with long hair that reach to her waist. She have light grey eyes and light pink hair with violet at the end of her hair, she also ties her hair into a large ponytail.
She often seen wearing Elite Guard's uniform with white stockings and black high heels.
She have a childish personality appropriate for her age and is a battle maniac, she flips like a switch where she becomes unstoppable. Because of this, she is treated with utmost care by those around her, and is often forbidden from joining any operations, which leaves her dissatisfied.
Suzuka describes her as "a girl who does not know the word 'restraint'".
Despite that she is not evil, she don't kill, wanting to live her life to fullest, fighting great battle and peoples remember her greatness, her existence.
Not much about Yume's background aside from she claim that she left her home at some point before the series start. In that time she also became a Toji, joined Ayanokouji Martial Arts School, became Elite Guard and obtain the Fourth Seat.
It is revealed that she being choosed by her current okatana at very young age. Follow the event, she also beated up many senior Toji, people praise her as a prodigy and she joined Ayanokouji Martial Arts School. But a disease caught up to her, forced her bedridden for a long time, no one care about her, her family abandoned her. Then Yukari Origami and Ayanokouji Martial Arts School's president Yuzuki Sagara visit, Yukari ask her what she want:"die in darkness no one know about or shine brightly for a moment and sear that brightness", and casually bring out a vial of Noro. Nothing is know afterward, but it is safe to assume that she accept the Noro vial, became a half-Aradama, continue to live and became Elite Guard, obtain the Fourth Seat.
Master Swordsmanship: Yume is extremely skilled in kenjutsu, capable of earning the fourth seat of the Elite Guard at a young age. She easily take on both Kanami and Hiyori at the same time, albeit those two focus more on escape than take her down. According to her profile, her swordsmanship far exceeds that of Maki Shidou who is a two-time National Champion and the First Seat of Origami Family's Elite Guard. She is also capable of overwhelming Mai and keep up with Sayaka for a while before being outclassed by both of them. She can also easily take on multiple enemies at the same time.
- Swordsmanship Style: Ten'nen Rishin-Ryu (天然理心流?) - A style whose strength manifests more in actual combat than in the use of shinai matches. This style adopts kenpo techniques compiled during the Shinsengumi period, and stresses the importance of confirming kills.
Immense Speed: She possesses great speed and swiftness, capable of keeping up with Sayaka, a fast Toji. She even defeat five Toji simultaneously in a short moment.
Okatana: Nikkari Ao'e (ニッカリ青江?) - An altered tachi whose length is shortened to that of a wakizashi. According to folklore, the name "nikkari" came from the laugh of the ghost of a woman that this sword slayed.
- Her birthday coincides with the celebration of Hinamatsuri.