The neighborhood has been designated as a redevelopment area, but the pet Mimi does not want to leave. Although the three brothers are sorry to see Mimi get quickly and dramatically old, they are also annoyed by her. Under the first snow of the year, Mimi returns to the old crumbled house. The biggest virtue of An Old Dog is “sentiment”. The film asks us what we have forgotten in this era where the old houses are crumbed to raise house prices on the pretext of redevelopment. That is why Mimi returning to her old house is more of a restoration of a precious value. The sentimental drawing style is just as touching as the story itself.