Ayame-senpai wa Boku to Himitsu no Keiyaku wo

On his way home from school, Mitsuya Daiki - an ordinary high school student - finds a girl covered in wounds. Upon closer look, he finds that the girl has animal ears, but she licks Daiki's ears and leaves. Daiki begins to wonder if it was just a dream, when Sakuragami Ayame appears upon him...? After telling her of the ability of Daiki's ears, Ayame feels responsible for dragging him into this, and proposes an oath of absolute servitude to protect him at all costs!