Hinagiku's birthday is coming up, and her mother asked her if she would be spending it with someone she liked, which makes her become anxious around Hayate the following morning. Both Hayate and Hinagiku find unsigned love letters addressed to them at school, and they both think that each other might have sent the letter. They later meet the the appointed place in front of the kendo dojo, but find out that it was Kōtarō Ayumamiya who sent the letters in order to show Hinagiku that he could defeat Hayate. Hinagiku then leaves, mad at Hayate for saying that she wouldn't do anything girly and lying that he didn't expect the person who wrote the letter to be Hinagiku. He challenges him to a game of cat's cradle, though loses terribly.
学年末試験当日、ハヤテはいつものように登校し、見かけたヒナギクに挨拶をするが、なぜか避けられてしまった。ハヤテを意識して避けてしまったのには理由があった。教室で席についたヒナギクは、自分の机の中にラブレターが入っていることに気がついて…。
