The gang comes back to school after the summer break and Konata is in a good mood because she has become hooked on Marimite. Miyuki is forced to go to school without her glasses because she broke them. Tsukasa recieves her first cell phone, but its life is very short after Tsukasa leaves it in the washing machine. On Lucky Channel, Shiraishi follows up on a fan's request for a certain hairstyle.

Tsukasa gets a new cell phone. Kagami teaches her how to text message. Tsukasa text messages Kagami to the point of sheer annoyance. Konata invites Kagami and Tsukasa over to her house and they forget to do their homework.

The girls go to a concert entitled "The Jam of Haruhi Suzumiya".

Kagami explains how much her pet goldfish has grown.

Konata actually finishes her homework, Ms. Kuroi accidentally erases a saved file in one of Konata's games, Miyuki talks smack about Ms. Kuroi, and Konata's dad is thinking about remarrying... or not! April Fool's!

The girls enter their third year of high school, and they see who's in what class for this year. Once again, Konata, Tsukasa, and Miyuki are in the same class, but Kagami is in a different one from them. Meanwhile, Konata's cousin Yutaka and her new friend Minami Iwasaki enter their first year of high school.

On Lucky Channel, it's announced that Akira will have a live concert next week.

It's almost time for the school's culture festival. While the girls are preparing for their classes' themes for the festival, Patricia proposes that she and the girls in her class should do a cheerleading act for the opening ceremony of the festival. Patricia "persuades" Konata into performing the routine with her, who in turn gets Kagami, Tsukasa, Miyuki, Misao, and Ayano to do it as well.

Akira Kogami finally makes an appearance on the actual show, although she and Shiraishi are still on bad terms.

Before the opening ceremony, the girls practice the cheerleading act one last time to the song, "Motteke! Sailor Fuku!"