In Japan, professor Tatsuo Kusakabe and his two daughters, Satsuki and Mei, move into an old house to be closer to the hospital where their mother is. The kids find that the house is inhabited by tiny animated dust creatures called susuwatari—small, dark, dust-like house spirits.
One day, Mei sees two white, rabbit-like ears in the grass and follows the ears under the house. She discovers two small magical creatures who lead her through a brier patch and into the hollow of a large tree. She meets and befriends a larger version of the same kind of spirit, which identifies itself by a series of roars that she interprets as "Totoro". Despite her many attempts, Mei is unable to show her family Totoro's tree.