This Reigai was modeled after Gaiden Morimoto (外伝森本, Forest Tale) the Head of the Morimoto house, and the 8th Division captain who was killed by the orders of Central 46, but died fighting off 6 captains of the Gotei 13. Muramasa Sumato chose Gaiden for its strength and its vast knowledge of the Morimoto Clan's powerful technique Getsukujin (月鎖陣 Moon Chain Battle Formation). Gaiden is also the father of Shiro Morimoto.