Aki Aoi is one of the main characters in the anime series 'Aki Sora.' He is a gentle and kind-hearted high school student who finds himself entangled in a complex relationship with his twin sister, Sora Aoi. The series explores themes of forbidden love and taboo relationships, with Aki often caught between his feelings and societal norms. His role is pivotal as he navigates these emotional challenges, making difficult choices that impact both his life and those around him.