vol 5, 9 pages before chapter 40 (you guys don't print any page numbers so I can't be more accurate)
. there is a box at the bottom left that has no text. the image in which the text box is in is of taiga having a towel on her head standing in front of a door with her back against the wall.
Other dialogue on the page is:
"Is it okay?"
"Yeah, I-I think it is"
"Aha!, so you're a closet klutz too, eh?"
and some other stuff.
Also, I think I spotted something like this in the amazing angel luna omnibuses at some point. Unfortunately, I don't know where it is, and I can't check because I read it at the bookstore :/