Tachibana no Oyassan, father of Isana Tachibana and proprietor of the restaurant employing Merry Nightmare, oversees Yumeji Fujiwara’s care during the boy’s parents’ absence, ensuring stability in his daily life. A prominent scar marks the right side of his face, though its origin is never detailed. His perceptive nature emerges when he challenges Merry’s choice to depart Yumeji’s household, spurring her self-reflection. Calm and steady, he anchors those around him amid encroaching supernatural turmoil. His role centers on familial guidance and managing his restaurant’s daily rhythms, with no expanded personal history or narrative evolution beyond these defined responsibilities.