(au where Tsukasa is a light knight and Rui is a dark mage)

The light and dark kingdoms have not been on the best terms for a long time. It was not a war, but the inhabitants of both countries despised each other, believing that several hundred years ago they had ruined the lives of others. Sometimes knights from different kingdoms clashed in battles. The sorcerer, Rui Kamishiro, who possessed strong dark magic, especially interfered with the bright kingdom. However, no one knew that Rui's magic was gradually killing him - it was a terrible mara that was gradually turning his hands black and his hair gray. Because of this, he suddenly disappeared and everyone thought he was already dead.

A young knight of the bright kingdom, Tsukasa Tenma, once walked through a dark spring forest. It was full of ruined kingdom buildings and magical herbs. He was riding a horse, looking around, until he suddenly saw a familiar silhouette. The knight quickly dismounted from his horse as Rui turned to him and frowned. He didn't attack, but he didn't say anything either.