10-year-old Satsuki and her 4-year-old sister Mei, move into a house in the country with their father to be closer to their hospitalized mother. Satsuki and Mei discover that the nearby forest is inhabited by magical creatures called Totoros (pronounced toe-toe-ro). They soon befriend these Totoros, and have several magical adventures.

	Mei is a single-minded, persevering child. Stubborn yet cheerful, she is like her older sister in that she is persistent and not timid. But with her initial shyness and tendency to few words, she seems to be even more observant than Satsuki. For some reason she doesn't fear goblins (Totoros), and the goblins that open up to her because her child's world has not yet been tainted by the common scene of adults-but this may also be due to her loneliness. Even Satsuki must bear up, but not having her mother around is an even greater hardship for a four-year old. Yet Mei is a bold, happy girl, without any dark shadow sin her personality. She runs after her older sister and imitates her. But if she comes across something interesting she becomes obsessed with it and forgets the way home or time, upsetting her older sister.
	A window stretches to become a door when a person would like to board it to travel. With its multiple caterpillar-like legs,[1] it runs, flies, bounces, and hops across forests and lakes to reach its destination, making whole rice fields sway in its wake. Its eyes shine a yellow light brightly like headlamps to guide it. Mice with glowing eyes taped next to its destination sign on its back and from its rear serve as tail lights. The Catbus is seemingly able to take its passengers to any destination they desire, even if the passenger (or the bus itself) lacks the knowledge how to get there; as is the case when Satsuki needed to find her sister, Mei. With its large elongated smile and its ability to appear and disappear at will, the Catbus is reminiscent of the Cheshire Cat from Alice in Wonderland. Often used to transport Totoros, in the film it makes an exception to help O-Totoro, the main Totoro, who is also the biggest. O-Totoro calls the Catbus and asks it to help Satsuki find her lost sister Mei. As Satsuki boards it, its destination sign changes to "Mei." After the sisters are reunited, the Catbus volunteers to whisk Mei and Satsuki over the countryside to see their hospitalized mother. After Satsuki and Mei return home, the Catbus finally leaves them, its body fading into the evening shadows.
	Satsuki is the older sister of Mei in My Neighbor Totoro. Satsuki can be irritable towards her sister Mei, for example at the end of the film when they find out that their mother won't be coming home from the hospital for the weekend, she scolded her sister for getting upset. Satsuki likes to think of herself as grown-up and caring for her sister. She is very lively, although not quite as lively as Mei. Satsuki is a good sister on the whole and looks after Mei to the best of her ability despite being upset about their ill mother. She is also very kind and responsible overall.