The story centers around Amaya, Iwasawa, and Uehara—three "annoying, spirited high school girls with zero motivation"—and their classmates. Their daily life is "what happens when there is nothing happening."
As homeroom begins, Ms. Sumiko Yamashita gives her class a surprise pop quiz which contains the question, "What is your teacher's name?" Mei Yanase, being the only one to answer correctly, is made the class representative, while Kanaka is made the MVP for her answer "Hikaru Jinguji", which Sumiko feels suits her better as a name. Afterwards, at lunch, the girls once again discuss nicknames, with Kanaka settling on calling Ayuko by the nickname: "Yukon". After school, Ayuko tries to get Ms. Yamashita's attention by calling her "Jinguji-sensei", but switches to "Yamashita-sensei" when she doesn't get a response.
Summer vacation begins and Ayuko receives a text asking to meet up with Kanaka and Saki. The girls then spend the day doing some of the same things Ayuko had done by herself at the end of the previous year's summer. Afterwards the girls spend the rest of the day at the ocean, enjoying the sunset together and promising to meet up the next day. While drying off at her home at the end of the day, Ayuko looks at the starry sky.