Angie's shameless Trolling of Yuki and Mina in chapter 35, especially the descriptions of their time in Siberia, then followed by Yuki's reaction when she finds out Angie's a guy.
The flashback in Vol. 7 to Akira and Angie's ritual ordeal, and Sanin's comment about why mankind invented underpants.
"It's not modesty or anything like that. It's just...It gets in the way, y'know? Bouncin' all over when you run..."
