These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
In "Matsuri In Rehab", Miu is hit on the nose with a rubber band, is kneed in the shin, then gets dizzy and falls flat on her face, all within two pages. The other girls think it's funny.
Chika: Miu! Come to my arms!
Miu: Chika?! You do love me, after all! *Starts running* Chika! I love you too! *Splat*
Les Yay: Miu likes to invoke this. The other girls aren't very receptive.
No Yay: Occasionally Nobue's Cuteness Proximity manifests in creepy ways, like staring at Ana in the bath or trying to kiss Matsuri. Chika tries to keep her sister from doing anything she might regret, while Miu just cracks jokes about it.
Memetic Mutation: Ana's facial expression (Google "gununu" for details) has become a popular visual meme.
Memetic Molester: Nobue. Sometimes her affection for Ana and Matsuri seems not entirely innocent.
Moe The whole cast, really. The English dub just takes this further casting younger girls near the characters' ages with all the adorable squeals and voice cracks that implies.
Superlative Dubbing: The studio opted for the uncommon practice of hiring actual girls very near the ages of the characters to get a more authentic dynamic among the cast. And it works.
Tastes Like Diabetes: The anime's opening and ending sequences. The show itself manages to avoid this thanks to its muted, deadpan delivery.