Houjou Arei

Houjou Arei (北条彩鈴) is a student of Tokiwadai Middle School, who appears in Toaru Kagaku no Railgun: Astral Buddy.

Appearance
Arei has red eyes and messy black hair which she ties in ponytail. In her first appearance, she wore a Tokiwadai jacket. Underneath she wears her full body suit along with her skirt.

Personality
Normally stoic in her expression, she is however quite merciless when it comes to her enemies, beating down Makigami Komaki so much that even Yumiya Iruka showed concerned that she was overdoing it. She also enjoys it when her opponent is strong enough for her in battle, as with the case with her fighting Hokaze Junko, after she momentarily bested her and making her bleed from her nose.

In spite of this she does value her friend Iruka, as she concedes to her wishes even if interrupts her love for battle, and shows concern over her well-being especially when it came to their plan against Junko and Shokuhou Misaki. After her escape and Iruka's capture with their mutual defeats from Junko, Arei tries to fulfill Iruka's wishes of wanting people to admire Junko, and describes her as an older sister who loved her little sister. Indeed, she hoped that Iruka would take a different path than her and her boss.

Later during her interactions with her older brother, Houjou is shown to have a more tender side to her personality, as seen where she was mildly annoyed and embarrassed by her brother's teasing and care for her and even blushed slightly as she annoyingly told him that she wasn't a child anymore, showing a close familial relationship with him.

Background
Not much is known about her past, though it is shown that she practiced using kunai on target practices when young. According to Nogi Yasuhito, she belongs to certain ninja clan which has been exterminated and is extinct in the present.

Before entering Tokiwadai, she belonged to another middle school. Despite being a Level 2, she was accepted into Tokiwadai as a technical exchange student because her highly specialized skills and abilities were considered equivalent to a Level 3.

Abilities
Her ability is called Whisper Bell (感情音叉). It allows her to hear people's emotions as sound. She has trained herself to interpret this emotional sound as locations, directions and distance in 3D space. She is only Level 2, but because of her highly specialized skills and her ability to apply her power she was considered to be equivalent to a Level 3. Because of this, she was allowed to enter Tokiwadai Middle School.

Equipment
During her last battle with Hokaze Junko, she made use of Hard Taping Custom (発条包帯・改) and an electric potential elastic suit to strengthen her physical abilities. This also allowed her to move about even after being beaten by Hokaze Junko.

In her battle against Shirai Kuroko and Shokuhou Misaki, she utilized kunais.