Shimozuma Rairen stands as a loyal steward of Ishiyama-Honganji and a dedicated follower of the Buddhist leader Kennyo within the Honganji Rioters faction. He actively supports Kennyo's struggle to safeguard the Honganji temple complex. Historically, he lived from 1537 to 1626. Physically, Rairen possesses a shaven head and carries a scar, marking him as a warrior-monk engaged in the Sengoku period's violent clashes. He features specifically in episodes 11-13, 15, 16, 21, and 25 of the third season, where his actions focus on the Honganji's defensive campaigns alongside Kennyo.