After Hayate the Combat Butler Vol. 25, 26 and 27 serve as something of a bridge arc. They don’t tell a complete story in their own right, but instead sort of continue in the shift in the status quo started by Volume 25.
At the end of Volume 25, Nagi had to come to terms with the fact that she simply cannot spend her way out of problems anymore. In the past 24 volumes of the series, she and Hayate, combined, were Batman. Hayate had Batman’s power of omnicompetence, and Nagi had Bruce Wayne’s superpower of money. Now, she no longer has that – and to regain her fortune has to acquire an apartment building, and then rent it out to tenants in order to regain her funds.
Old Friends, New Context
Fortunately, this arc sets up that Nagi basically had personally inherited (sort of – the inheritance came through Klaus) an old manor that had belonged to her mother, that was suitable for converting into Apartments in a very Maison Ikkoku-esque manner. So, the issue over these two volumes giving the building a makeover, finding tenants – oh, and bringing over Tama.
If you’re expecting an addition of a whole bunch of perfect strangers to the cast as Nagi’s tenants, you’re mistaken. Nagi’s first tenant basically ends up being Chiharu, one of Nagi’s classmates, Student Council Vice President alongside Hinagiku, secret otaku, and Sakuya’s maid. Once Chihiru moves in, she and Nagi hit it off really well, and in a way that basically sets up her role in the story – to serve as Nagi’s wake up call.
Rocking the Boat
In particular, Nagi wants to become rich and famous selling doujinshi… except as has been established in this series, Nagi’s doujinshi is… bad. However, because Nagi had been basically living in a bubble when it comes to criticism of her work, and she’d become invested in the idea that she was a genius at everything, she’d never really been taken down a peg. Yes, she’s lost her fortune, but that was through actions taken that would knowingly cost her that fortune for the sake of Hayate.
Consequently, these two volumes basically put a focus on 1) Nagi meeting someone outside of her regular circle who she trusts and whose opinion is important to her, and 2) Getting gently made aware by that person that no, her manga isn’t perfect, if she wants to succeed she needs to take steps as an artist and a writer to improve – but it’s also okay if she’s not perfect right out of the gate, as nobody is.
Consequently, it looks like Nagi learning this lesson is going to be the focus of her character arc over the next few volumes. This volume also sets up a group of shadowy people who are really interested in a few bookcases of old, presumably magic-related, books in old bookshelves in the building, but all that really happens related to that this volume is them launching a few attacks on Hayate.