I Want to Go Back to Being a Normal Girl, but Please Buy My Character Song
Nagi asks Hayate what type of girl he likes, after reading a romance magazine which states that Nagi's zodiac sign, Sagittarius, will face a crisis in terms of romance. Hayate tells her that he likes girls that are normal and makes a passing remark that Nagi "wouldn't understand". Nagi runs off in rage, determined to learn how to be 'normal'. Nagi meets Ayumu Nishizawa and comes to the conclusion that tagging along with her will help her learn how to be 'normal'. After a day of following (and bothering) Ayumu, she invites Nagi to stay at her place. Ayumu gives Hayate a call, at Nagi's request, to inform him that Nagi will be staying over. It turns out that Hayate has been following them. Just as Hayate was about to leave, Isumi calls in distress, trapped at the top of a nearby tower. Wataru rushes to save her before Hayate, but it was ultimately Hayate who did most of the work.
Aired 09/12/2007EP 37 - I Want to Go Back to Being a Normal Girl, but Please Buy My Character Song

Hayate the Combat Butler
Hayate Ayasaki's life wasn't great, but when he loses the job he used to support his good-for-nothing family, and his deadbeat parents sell him to the Yakuza for cash, it really hits rock bottom! Faced with having to pay off the huge debt before he's converted into black market organ parts, a desperate Hayate decides to kidnap oddball heiress Nagi Sanzenin for ransom... but when even that goes wrong and he accidentally ends up rescuing Nagi from other kidnappers, it turns out that Hayate is the bodyguard that Nagi has been looking for! So now he's the Sanzenin family's butler, and… maybe… it might be the start of a potential romantic relationship… assuming Hayate can survive the on-the-job training, of course.
(Source: Sentai Filmworks)