I initially thought she is a woman at first then I duped myself into thinking "Oh, it's that kind of manga with cute trap-like guy". Glad to see that I was wrong ?
@nfzeta The joke is that the Male MC tried to shift the blame for not noticing her as a girl to the "Characterization Trick", a common narrative trick that relies on audience's assumption, even though we as the "true" audience of this manga weren't really fooled by said trick thanks to the hints. The Male MC is basically just pulling his ass to excuse his density.
Damnit, I was tricked. I was mostly skimming through the conversation. On closer inspection, it should have been much less of a surprise but I'm glad it was.
Assumed it right away, based on her blushing, but became completely obvious once I saw the long eyelashes for her eyes as well as the author trying to hide her figure in the first few pages.