Orignally, for the movie My Neighbor Totoro, Miyazaki was thinking to cast only 1 girl of 7 years old but he thought that would not be the best choice and instead he created 2 girls with an average age of 7 years.
It’s possible to find some arts where we can only see 1 girl that looks older than Mei and younger than Satsuki.
The older sister, Satsuki, is 10 years old. She was born in June 1947. Despite her young age she knows how to cook and she is mature. She is energetic and likes her family. She worries a lot about her little sister and doesn’t hesitate to run after her for many hours.
She would like to have nice and long hair like her mother.
The younger sister, Mei, is 4 years old. She was born in Tokyo in May 1954. She likes her sister a lot and imitates her several times during the movie. She is stubborn and curious. She is waiting with impatience the return of her mother so they can sleep together.
In Japanese, ‘satsuki’ (五月) means the month of May. Her sister’s name, ‘Mei’, is also May in phonetic.