あやめ先輩は僕とヒミツの契約を

平凡な高校生・三ツ矢大樹は、学校からの帰り道、満身創痍の少女を見つける。On his way home from school, Mitsuya Daikiー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 Daikis 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 Daikis ears, Ayame feels responsible for dragging him into this, and proposes an oath of absolute servitude to protect him at all costs!