I know feeling like you can't waste food is one of those things that varies from person to person anyway, but I would've thought to ask about a way to take my left overs home before anything else. Is that sort of thing perhaps uncommon in Japan?
Oh man... after seeing the last page and comments... I actually didn't think of wrapping it for takeout either XD!!! DARN!! I am the type that doesn't like to leave food on the plates too so I would've tried chugging it all down too, oof!!