A large part of the fic's humor comes from Shikako's running commentary on numerous situations. One such point is when the squad first encounters Zabuza as he scares them by... talking to them while hiding in the mist. While the effect is actually scary, Shikako can't help but remark on this and wonder why he's still talking.
Shikako(in her head): Hello, my name is Zabuza Momochi and I'll be your assassin this evening.
The entirety of the water fight scene. Especially when Haku pushed Zabuza into the water.
Come to the dark side, we have cookies.
The "fight" between Kiba and Shikako in chapter 32.
Chapter 61: "Everyone is making such dramatic entrances today."
The Land of Tea arc, where Aoi pulls out the Sword of the Thunder God and the first thought Shikako thinks is 'Thatů is a lightsaber'
During the same fight, she uses his ownTrash Talk tactic against him. Seeing normally-civil Shikako annoyed enough by an opponent to go all out with the trash talk is hilarious enough, but she does it... by accusing him of sleeping his way into his rank.
"With hair like that, you look like a girl from the right angle."
Jiraiya: You kids do seem to land yourselves right in the middle of some serious messes.
Kakashi: You don't know half of it, I've been gone for a week and come back to find they've done an A-rank without me.
Sasuke: Three. Technically, we did three A-ranks without you.
Sasuke: One of them started aboutů half an hour after you left