Grandfather, the chief priest of a family-operated shrine, oversees a significant sliding door intentionally left partially unpainted. This door initially ignited his granddaughter Aiko’s childhood artistic ambitions yet later remained an object of unresolved curiosity. When the mysterious Souji arrives unexpectedly, the grandfather extends compassionate hospitality by offering him shelter, a decision made despite Aiko’s initial objections. This act reinforces his stabilizing presence within the household and facilitates Souji’s pivotal stay, which ultimately reignites Aiko’s artistic pursuits and catalyzes her personal growth.