Based on a fan translation of *Donten ni Warau Gaiden* chapter 12, the character Yamagata is mentioned during an interrogation at an experimental facility. Abe no Sousei questions test subject Tora about the highest commanding officer overseeing the experiments. Sousei explicitly states that "Yamagata-sama did not take command" of these operations, indicating Yamagata's potential authority. Sousei further explains a superior officer from the army should have visited the facility, implying Yamagata's connection to military leadership and oversight responsibilities. This context positions Yamagata within the military hierarchy relevant to the secret experiments.