In 1958 in Japan, university professor Tatsuo Kusakabe and his two daughters, Satsuki and Mei, move into an old house to be closer to the hospital where the girls' mother, Yasuko, is recovering from a long-term illness. Satsuki and Mei find that the house is inhabited by tiny creatures called ''susuwatari''—small, dark, dust-like house spirits seen when moving from light to dark places.<ref group=note>The susuwatari are called "black soots" in early subtitles and "soot sprites" in the later English dubbed version.</ref> When the girls become comfortable in their new house and laugh with Tatsuo, the soot spirits leave the house to drift away on the wind and find another empty house.