Hayate the Combat Butler 5
In this volume, Hayate faces a duel to prove himself as a first-class butler, then has to face a test of courage in an old school building, tries to find a special deadly technique, then has to protect Nagi aboard a startlingly... familiar? ship. Meanwhile, Nagi herself encounters her rival for the first time and Wataru has a crisis of understanding over a woman's feelings.
This story was made for me by the search for the special deadly technique, a hunt that leads us into the next volume as well. Upon meeting two other butlers, Hayate has it in his head that he needs one in order to successfully protect Nagi (and given that he challenged everyone who wants her fortune to go through him first, he's likely right). But these things rarely just show up in, say, the library or at school. Still, it doesn't stop him from looking in all those places.
We also get to see Izumi in her main work in this book, to an extent. She's the sort of vacant character I usually don't dislike, but also don't really care about. But for some reason, Isumi really amuses me. :)
Hayate the Combat Butler 6
I said in my review of vol. 5 that the search for the secret deadly technique would continue into the next book, and here we go!
After failing to turn the physically lazy Nagi into the winner of a race at school, Hayate is about to be fired. But there's a way out - if he can complete training at the Tiger's Pit for Butlers, he will be allowed to return. However, things are never as simple as they sound in Hayate's world, and he ends up having to deal with a violent nun, a ghost and worst of all - practical butler experience.
The Tiger Pit is a weird arc, absurd in the way I've come to expect from this series, but I think it might be one of my favorites. The references aren't always recognizable to me, but enough are to give me a grin.