Gemstone Girl

She is, as the nickname implies, a Gemstone who's name has been unrevealed and who's power hasn't been detailed. She debuted in Toaru Majutsu no Index Light Novel Volume SS2.

Her most distinctives feature are: the fact that she walks around with a suitcase handcuffed to her right hand, her young looks which imply that she should be around her late teens and that she wears a one piece dress that has been described as "covering so little, that isn't much of a clothing". It should be noted that she is unusually beautiful for someone of her age, gifted with a gorgeous face and a feminine body line.

She meets Kamijou Touya in a train station while she was lost; in a very Kamijou way Touya selflessly approached her without her requesting any help gave her proper instructions on where to go and after which they parted ways. She reappears later in a bar where Misaka Tabikake and Kamijou Touya had just became acquaintances, at that point she is making a run from her pursuers. As soon as Touya sniffed trouble he made a run out of the place at mach speed, however the Gemstone girl was running right behind him.

The pursuers followed them with such resilience, that Touya, the gemstone girl and Touya's kouhai needed to fake their deaths in a plane crash in order to shake them off.

(Source: Toaru Majutsu no Index Wiki)
(Updated by Aezile of Toaru Majutsu no Index club)