A 2nd-year student at Tokiwadai Middle School, one of the city's top elite schools. Known as Tokiwadai's Ace (addressed as "Misaka-sama"), she is the 3rd-ranked Level 5. Ability: Railgun / Electromaster. 14 years old. Height: 161cm. Mother: Misuzu Misaka. She has a straightforward, refreshing personality. A girl with refined features and shoulder-length brown bob-cut hair. Possesses a strong sense of justice and is a hard worker. A competitive and active tsundere (big-sister type). She has a long-standing, complicated bond with Touma. Combat Style: Railgun (primarily firing arcade coins accelerated by electromagnetism). Lightning Spear, Iron Sand Sword, magnetism, electronic manipulation, and cyber-terrorism. (Reached Level 5 from Level 1 through pure effort.) Weakness: Running out of battery (physical exhaustion). Academics/Intelligence: High physical ability and martial arts skills. Academically excellent, capable of solving high-school level problems, and possesses a great memory (a model student for educational guidance). Interests: Plays the violin, loves Gekota (frog character) fancy goods, and enjoys manga.

A 1st-year student at Tokiwadai Middle School. Member of Judgment, 177th Branch. Level 4 Teleporter. Wears her hair in twin tails. Her catchphrase is "Judgment is on the case!" Speaks in an elegant, lady-like tone. Height: 152cm. Serious about her duties, but a pervert with heavy, obsessive love for Mikoto and Guest. Refers to Mikoto as "Onee-sama" and Guest as "Onii-sama".

Uiharu's best friend, a 1st-year student at Sakugawa Middle School. An innocent girl with long black hair. Sometimes worries about being a Level 0. Sensitive to trends and urban legends. Height: 160cm. 13 years old.

A girl in the 1st year at Sakugawa Middle School and a member of Judgment's 177th Branch. Kuroko's colleague. Level 1 Thermal Hand. Excellent and gentle, always speaks politely. Expert in information gathering and hacking. Height: 153cm. 13 years old. Short black hair with a flower ornament.

A 2nd-year student at Tokiwadai Middle School. A girl with blonde hair and honey-colored eyes. Height: 168cm. On bad terms with Mikoto. The 5th-ranked Level 5. Ability: Mental Out. Known as the Queen of Tokiwadai and leader of its largest clique. Clique member: Junko Hokaze.

The 4th-ranked Level 5. Ability: Meltdowner. Self-centered and arrogant (but a caring big-sister type to her team). Long brown hair. Leader of ITEM. Ferocious and merciless toward enemies.

Level 4 Offense Armor. Frequently uses the word "Super" as a verbal tic. A fan of B-grade movies. Member of ITEM. Always speaks politely. Brown hair, wearing an orange sleeveless hoodie over a shirt and denim shorts. Also seen in a loose-knit one-piece dress.

Level 0. Verbal tics include "Ultimately..." and "...is the point." Specialist in traps, bombs, and kicking techniques. Member of ITEM. Long blonde hair and wears a beret. Playful and optimistic.

Quiet and kind. Level 4 AIM Stalker. Member of ITEM. Wears a pink tracksuit and has black hair.

The strongest in Academy City, the 1st-ranked Level 5. Ability: Vector Transformation (manipulating the direction of anything he touches). Rough and violent. Height: 168cm. White hair, red eyes, wears a white and grey striped T-shirt and navy jeans.

The 2nd-ranked Level 5. Ability: Dark Matter. Fickle personality, leader of SCHOOL. Blonde hair and wears host-like clothing. Member: Measure Heart.

A Level 0 transfer student at A Certain High School. Her dream is to make everyone happy through singing. Long pink hair. Casual wear includes a grey newsboy cap, a white blouse dress, and jeans. Performs street lives and distributes music online under the name ARISA. A bright, positive, and hard worker. Height: 155cm. Her singing voice possesses a miraculous power.

Spiky hair like a sea urchin. A Level 0, but possesses Imagine Breaker in his right hand, which negates supernatural powers and magic. Father: Toya Kamijou, Mother: Shiina Kamijou. Blunt and listless, but a good-natured meddler who is loyal and takes good care of others. Classmate and dormitory neighbor of Guest at A Certain High School. 15 years old. Height: 168cm. Possesses a misfortune-prone constitution. Catchphrase: "Such misfortune." First person: I (rough) / I (polite) / Kamijou-san. Summer: Orange T-shirt under a short-sleeved uniform. Winter: Red shirt under an unbuttoned Gakuran. White sneakers with red lines.

An apprentice nun of the Church of England. Possesses perfect recall of magical grimoires. First person: I (watashi). Sentence endings: "...nandayo," "...kamo." Selfish and has a huge appetite. Height: 148cm. 14 years old. Currently freeloading in Touma's room.

A 2nd-year student at Tokiwadai Middle School and a Level 4 Aero Hand. Daughter of the Kongo Airlines family and a friend of Mikoto. On bad terms with Kuroko. Height: 163cm. Has an ojou-sama personality but is honest and cares for her friends. Friends: Kinuho Wannai: Level 3 Hydrokinesis (Float Dial), freely increases or decreases buoyancy. Maaya Awatsuki: Level 3 Hydrokinesis (Hydro Hand).

A member of Judgment and senior to Kuroko and the others. Level 3 Clairvoyance. Height: 163cm.

A member of Anti-Skill and a PE teacher at A Certain High School. Sloppy and blunt but cares deeply for her students. Height: 175cm. Sentence ending: "...jan." Often wears a green tracksuit.

A clone of Mikoto who moves at her own pace. Sentence structure: "...says Misaka as she..." First person: Misaka. Second person: You. Refers to Mikoto as "Onee-sama".

A clone of Mikoto with an innocent personality. Sentence structure: "...says Misaka, says Misaka as she tries..."