|Occupation||Trainee Railway Security Force|
|Affiliation||Japanese National Railway|
|Novel||RAIL WARS! Light Novel Volume 1|
Aoi Sakurai (桜井 あおい Sakurai Aoi?) is the main heroine and a member of the Tokyo Central Railway Public Security Office Fourth Vigilance Squad.
She has crimson hair which is tied up in bun at the back and light blue eyes.
She wears the normal security uniform which includes a turquoise tie, skirt, black pantyhose (also wears in School uniform) and black shoes with red shoe laces.
In her private clothes, Aoi wears dress and white underwear, and a boots without legwear.
She is a really tough girl that hates boys. She also isn't afraid to kill and is willing to take risks as seen in RAIL WARS! Episode 2 when she tries to defuse a bomb.
She was trained in hand to hand combat, weapons, and bomb disarmament training by her father who was a police officer.
- They met before the entering the Railway Academy. At first, she was very cold towards him. Later she came to trust him. In a later part of the series she developed feelings for him, he also eventually develops romantic feelings for her.
- They met at the opening ceremony of the Railway Academy. They soon became friends. She is the other female member besides Aoi Sakurai & Nana Lida of the Fourth Vigilance Squad.
Aoi sees Haruka Komi as a friend and comrade, as well as a rival in love.
- Expert Hand-to-Hand Combatant: Trained in martial arts since she was a small child, both professionally and by her father. She has repeatedly shown great agility and coordination in her attacks. In addition to having powerful kicks and punches, Aoi is proficient in counterattacks, takedowns, and body locks.