Getting to see Kaoruko enjoy herself with food is a joy in itself for Rintaro, and I'm super glad he told her upfront about it. The power of proper communication is amazing. Not only did she herself ultimately decide not to worry ("it'd be rude to him") and just be herself, what he said completely confirmed that she made the right choice on their date. That's right girl, you don't get to go out on dates often, so make the most out of it.
I feel like many other romances would've gone with the big eater girl skimping out on food for laughs, but not this one. Kaoru Hana be like: we don't do that here. This story treats its characters with respect.
ps. Mio has an older sister? I'd like to see her. And is that the donut lover pair having trouble picking snacks? Finally, that page 15 is Rintaro getting invited to a meal at the Waguri house. Our good boy finally meets Kaoruko's mother and little brother! Hoping for the best...