A cleaner is usually unnoticed, but in fact, she knows many secrets involving the Twelve Holy Knights that ordinary people don't know. "If you want to know a secret of the Holy Temple, ask a cleaner".

"Grisia Sun" is walking along the corridor when he hears the sound of piano. The music draws him to the room where it comes from. As he opens the door, what Grisia sees is...

This is not the first time the 38th generation of the Twelve Holy Knights have fought side by side. Their personality, their abilities, their meeting and their connection are all determined by one's wish. The question is... who wished for this to happen?