Kei Ayamine is a main heroine in the visual novel and anime series 'Muv-Luv Alternative.' Known for her stoic and reserved personality, Kei is a member of the elite 207th Training Squadron. She is highly skilled in combat and displays remarkable composure under pressure. Despite her distant demeanor, Kei deeply cares for her teammates and gradually warms up to the protagonist. Her tactical abilities and calm judgment make her a valuable asset to the squad and a memorable character in the series.