The reason he had never been to a roadside convenience store before because his servants in Tokyo mmuat have done the shopping, and his area must be too posh to allow them.
Haven't y'all read manga where the same thing happens with Ojou Samas who see stuff for the first time.
that conversation at the end, i was convinced it was just a coincidence and not intentional, especially as it was mostly from him... but she totally shattered the illusion with her last line