Rou Tenshi serves as the Celestial Priest at Ryukozan and is counted among its ten elders. He is the apprentice brother of Chou Shakurin, grandfather to Chou Soran. Rou Tenshi made a promise to reveal the truth about Chou Shakurin should Chou Soran win the Raten Tournament, a truth intrinsically tied to the ceremonial rules of the Tenshi position.

In the Raten Tournament, he helped orchestrate events to draw out the group Zensei, using the secret of Chou Shakurin and a secret art as bait. After Chou Soran's victory, Rou Tenshi moved to grant him the rights and knowledge to become the next Tenshi. Chou Soran, however, grew suspicious and refused to accept the ceremonial rules, an act which threw Rou Tenshi into a fury.

His history is deeply interwoven with fellow elder Riku Kin, who inherited power from his best friend and shares a past with Zensei. Another key relationship is with Den Shinchuu, a fellow elder and former apprentice alongside Chou Shakurin. In his youth, Den Shinchuu was sent to retrieve Chou Shakurin but returned legless and professing failure, though the true nature of these events remains obscured.