It is summertime for the girls; that means one thing: comfortable summer uniforms! Tsukasa and Kagami are fraternal twins, but Konata shows them the similar and different characteristics they share. Konata, Kagami, and Tsukasa each try to put their hair into a ponytail, just to see who looks best. Unfortunately, Kagami is the only one who cannot pull it off.

It is time for tests! Unfortunately, Konata cannot seem to concentrate on studying and instead reverts to slacking off and playing games. She tries to ask Miyuki about good study habits, but in the end she does bad on her tests. Tsukasa got help from her sister and this time got better scores, but Kagami's scores were still higher despite her own scores going down somewhat. Later, Konata and the Hiiragi twins go to a cake café but end up taking too much and must finish it all or pay an extra price.

Konata gets a new cellphone.

The girls learn how Miyuki became so knowledgable, how much she spaces out, and when she started wearing glasses.

Kagami, Tsukasa, and Miyuki go see Konata at her job. On their way, Konata calls and asks them to pick up a comic for her. When they arrive at Konata's workplace, they see Konata dance on stage and meet her coworker, Patricia Martin.

While studying with two of her classmates, Ayano Minegishi and Misao Kusakabe, Kagami realizes just how similar they are to Konata and Tsukasa.

On Lucky Channel, Akira holds her big concert... in a karaoke bar.

Konata and Yutaka catch a cold, and Yutaka's friends, Minami, Hiyori, and Patricia, come and visit her. They, Konata, and Yutaka discuss younger-sister-moe, Minami's lack of breasts and how Hiyori doesn't want Yutaka to read her doujin manga.

After seeing a TV program about how xylitol chewing gum can eliminate cavities, Miyuki decides to test this out. As a result, one of her fillings comes out and she has to go to the dentist.

Kagami and Misao play a video game together. Although Misao is terrible at playing them, she seems to be having more fun than Kagami who's playing to win.

Patricia tells Kagami what music she's been listening to lately and how much she would like to have a maid.

Miyuki tells her mother about her friends' opinions on Minami, but they seem to contradict with what Miyuki's mom recalls from Minami's previous actions.