修羅ノ庭 (Shura no Niwa)

Background
This song is featured on the albums KING&KNIGHT-ワン☆オポ！BEST vol.01-, Haru Album (ハルアルバム), Wonderful★Opportunity! vol.02 (ワン★オポ！vol.02) and Tenkyou-no-wagaku (天響ノ和樂).