I still am surprised that she doesn't understand that a hospitalized regular primary schooler looks leagues different from healthy gyaru extroverted high schooler. This conflict is so manufactured it still has its bar code stamped on. (Also lol the guchis come in pairs?)
Also if he's from an infamous thief guild or some shit, there's the answer "oh I've memorized dark guilds and recognized the iron claw mark on his shoulder" or wtv