Mikoto willingly gave a DNA sample to the researchers of the project after being told that it would help people who suffer from muscular dystrophy, a fatal disease. This made her a perfect candidate for the Sisters Project, which held the intent of cloning her for military use. She entered Academy City in elementary age, and distinguished herself as a child prodigy, initially starting out as a Level 1 and climbing her way up to a Level 5 esper. Mikoto is the daughter of Misaka Tabigake and Misaka Misuzu.

Mikoto gave a sample of her DNA to Academy City scientists at a young age. She is also known to always wear shorts under every skirt and dress she wears, which surprises an amnesiac Kamijou Touma as she is the only girl who wears shorts over her panties. She wears the Tokiwadai Middle School school uniform, sporting white loose/slouch socks and brown loafers with a light brown vest sweater over a white blouse and a grey skirt. She is also shown to have a complex regarding her chest, feeling inferior when compared to girls with bigger bust sizes. It then was changed to one with two little flowers since the Tree Diagram Remnant Arc, specifically, from Toaru Majutsu no Index II Episode 06 in the anime, or Toaru Majutsu no Index Manga Chapter 058 in the manga). Mikoto has chestnut hair and is often seen wearing a small hair clip (firstly a rather simple one in the early stages of the story. 5.2.1 Dengeki Gakuen RPG: Cross of Venus.5.1.2 Ookami-san to Shichinin no Nakamatachi.4.3.2 Toaru Majutsu no Virtual-On (game).4.3.1 Toaru Majutsu no Index (PSP game).4.2.1 Toaru Majutsu no Index Movie: Miracle of Endymion.4.1.5 Shinyaku Toaru Majutsu no Index SS.4.1.4 Toaru Majutsu no Index: Road to Endymion.4.1.3 Toaru Majutsu no Index: Love Letter Competition.4.1.1 Toaru Majutsu no Index Light Novel Volume SS2.

Mikoto misaka honey select card