I wonder if the fudged out conversations is a sort-of "respectful privacy" for a bf-gf phone call, or a demonstration of why Rintaro is forgetful, or it's just the mangaka simply fast-forwarding the details of the talk which isn't super important, but I also like how even without the exact words, it's possible to tell that it was a joyful conversation that inspired him to do try new things for his next cake.
But more than that, this was a very precious moment for his caring parents. A beautiful payoff for their patience with their son. I also love the beautiful little moments that show how his parents care for each other.
I read a lot of manga, but this one just makes me smile every time with each chapter. How does this do it?