When the resturaunt that Mayuko works at gets a large party reservation, Mayuko goes to the supermarket for ingredients.  Chie goes with her which turns out to be fortunate since Mayuko has never been inside a supermarket before.  After the party leaves the resturaunt, Chie sees fireflies for the first time and her father tells he about how Enohana used to be known for them - so to speak.  NieA still tries to figure out what the mothership means by the "sayonara" signal she picked up.