Koikishi Purely Kiss - Season 1

Based on the erotic game from Effordom Soft. A childhood incident binds Kaname and Elcia. Trapped in a burning building, Elcia was pinned under rubble. Kaname refused to abandon her, despite the seeming futility. As Kaname's strength was nearly spent, a knight of the modern day rescued them both. In the aftermath, they made a mutual pledge to become knights themselves, vowing to protect justice and righteousness above all others. Now, years later, that promise is fulfilled. They work together as knights, side by side. As they carry out their duties, a romantic affection begins to develop between them.