I had to stop reading twice to kick and squee, and when I got to the end I went back and read it all again. Oh goodness, these two are so cute! And wholesome! And they make so much progress! There have been a million and one manga that have used the "cute" "isn't it?" exchange without the guy clarifying that he was talking about the girl — but Yamaguchi pwns 'em all here and straight out tells her. And as if that wasn't enough, then he goes and shows that he's been paying attention to and learning her reactions and can read her nonverbal cues!
His grandparents are adorable, and I love that we can see where Yamaguchi-kun gets his glare. Also, we're totally nominating Koto-chan and Waku-chan for best wingwomen of the year.