Mitarai Ayane

Mitarai Ayane (御手洗彩音) is an esper who was working with Antikythera, one year before the main story.

Appearance
Mitarai has light-colored hair in a bob cut with front fringes. She wears a Shidarezakura school uniform and three hairpins in the shape of musical symbols (G-clef, F-clef, and quaver rest).

First Year Arc
Mitarai first appeared in Antikythera's HQ as she was monitoring the battle between the Tokiwadai students and Montgolfier's operatives, transmitting and receiving information with her ability while seated in a command chair with a foot bath.

When Hasekura Reiri broke into the headquarters, having detected and tracked the ultrasonic waves to their source, Mitarai attacked her, but her sonic attack was blocked by Hasekura's water ball, which Hasekura promptly used to engulf Mitarai in water and render her unconscious.

Abilities
Mitarai's esper ability allows her to transmit and receive information in the form of ultrasonic waves, which can only be decrypted using special devices. One of Antikythera's higher-ups was confident that even Tokiwadai's two Level 5s, Misaka Mikoto and Shokuhou Misaki, could not track the encrypted communications relayed via her ability back to them, though Hasekura Reiri detected it.

Mitarai can also perform a sonic attack in the form of a focused wave beam emitted from her mouth.

Trivia

 * Her surname has two possible translations. The intended reading, mitarai, resembles mitarashi, the term for a water receptacle used for purification before entering a shrine. An alternate reading is otearai, the Japanese word for a restroom or toilet. Both terms use the same kanji.