Grandfather

お爺ちゃん

He's a strict, stubborn grandfather whom Asuma is afraid of, but because he can't win against aging, he is currently being hospitalized for an illness. (Source: Tsukumimi vol. 1, "Character Introductions") [Spoiler] After Asuma's graduation at the end of the story, he retires from his duties at the shrine (allowing his grandson to officially take over). [/Spoiler]