Much of the OST can be included, but special mention goes to Natsu Koi Monogatari by UxMishi, performed at the Yumesaki High school festival live concert.
Die for Our Ship: Oh, the treatment Hinata gets from the Usui/Misaki shippers!
In-character, the manager of the Maid Latte cafe, Satsuki, is fanatical about all things moe. She's pretty much Ken Akamatsu in a skirt. And an Usui x Misaki supporter.
Sakura's character is all made for this purpose. There isn't a single moment where she's not acting moe from some angle. You can't blame the hard-boiled Misaki to care for her when she's about to tear up.
Yukimura too. It's a wonder he doesn't just get kidnapped walking down the street.
Theme Pairing: There is apparently a miniscule fanbase for Shizuko/Kanou that ships them mostly because they both wear glasses and are the voice of reason for their respective Those Two Guys/Those Two Girls pairs.
With the recent revelation that Shizuko apparently has a thing for glasses, maybe this isn't so farfetched after all.
Unfortunate Implications: A common criticism from reviewers is that the ultimate message being given is that no matter how smart or strong you are if you're a girl your natural place is being subservient to men and that you'll never be better than them.
Later chapters mitigate this to some extent by turning the same "don't try to do everything by yourself" message around onto Usui.