Masamori Sumimura (墨村正守, Sumimura Masamori) is the firstborn son of Sumiko Sumimura and Shuji Sumimura. While he excelled as a Kekkaishi, he was dissatisfied with the restrictions placed on him as a non-Successor, and eventually left home. He joined The Shadow Organization, founding and leading its Task Force (more commonly known as the Night Troop). Masamori is later promoted to the 7th seat on the organization's executive committee, the Council of Twelve, a position vacated by his former mentor Mudou.