My admittedly bad joke is based on "say gex" where you swap the first letters (edit: and an incorrect assumption that the phrase came earlier than gex alone. I don't remember when I first saw "say gex"; I thought that was forever ago).
Also ackchyually you're thinking of portmanteau rather than...
Excuse me for asking, but where in which chapter(s) are Xiao Hua / Rosette mentioned? Is it just the monster flower thing gifted to him earlier in the series? Because I don't remember this name at all.
Sorry for nerding but page 6 broke my immersion. I realize if a girl tilts her pelvis forward then the rear of the skirt will lift a bit, but this frame is also drawn like she moved quickly in a low gravity environment to cause the hemline to float when it wasn't previously portrayed as a poofy...