Hoshino Hikari

A first-year student in the Standard Course. She's cute, and she knows it. 16 years old.
Hikari is the sort of person who's nice to everyone, and gets roped into everyone's troubles as a consequence.

In reality, she's an Agency spy who's been enrolled into St. Leanne Girl's Academy with a mission to uncover the plans of its Principal.

Having taken part in a ritual held before the school's opening ceremony, she was, to her surprise, bestowed with the grace of Virgo, becoming one of the Twelve Angels of the Zodiac.

Spoiler

Her mission only kept going off rails from there. She was thrown a year into the past, and ended up accidentally charming her fellow agent Hime with her zodiac powers.

It's increasingly looking like Hikari has found herself dancing to someone else's tune.