Kotoha switched over to video specifically to see Fumi's reactions to the (terrible, terrible) puns, so she did indeed see that twitch. She will mentally note this down as a victory and continue with the conversation. A brief check of the astrology document and she's managed to translate 'Cancer' into something more normal.

"Cancer...that's July, then? Under our system, you'd be a Crustle, which is an autumn sign associated with the elements of Rock and Bug."