Part 1 Kana and Fujioka compete over grades they get for class tests throughout the day where the loser has to act like a dog for the winner. Even when Kana changes her grades to make them higher, it doesn't stop Fujioka from scoring better than her on all the tests.
Part 2 When Chiaki dodges the subject of her grades when Kana asks about them, an annoyed Kana drinks all the milk in the house causing her not to feel so good. When Chiaki informs her that Haruka planned to use milk to make tonight's dinner, a stubborn Kana makes a failed attempt to make a decent dinner. When Haruka arrives home, a defeated Kana decides to go buy milk.
Part 3 Fujioka makes a love confession to Kana which gets the girl to seek consultance from "Chiaki-sama." Getting annoyed with Kana bothering her, Chiaki once again has Kana think that Fujioka's confession was a challenge leading Kana to be on the defensive the next day at school.
Part 4 Fujioka is invited over to the home of the Minami sisters by Kana to "make peace" and have him eat from the three pans of curry that Kana and Chiaki made from the previous night as dinner. Haruka and Chiaki wind up being on friendly terms with Fujioka, which leads Kana to get annoyed enough to drive him out of the house with one of the leftover pans of curry.