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.
Crowning Moment of Funny: Whenever Hikaru trolls someone. Such as asking Ema about her relationships with Natsume and Azusa while Natsume is driving and Azusa is also in the car, or when he walked in on Ukyo teaching Ema to chop meat and proceeds to point out that he is blushing. Also apparently he created a chart labeling the odds of each of the brothers winning Ema over.
Crowning Moment of Heartwarming: Louis comforting Ema after she finds out she's adopted by telling her that he is also adopted. The message that family doesn't need to be related by blood for them to love each other is just so sweet.
Incest Subtext: Of the Twincest variety. Reminiscent of Ouran High School Host Club's Hikaru and Kaoru. Tsubaki and Azusa practice extremely intimate lines with each other for their voice acting jobs without a care in the world. When Ema hears them she gets quite flustered. They don't even really bother correcting her. Also very gentle with each other outside the studio.
Squick: How some feel about preteen Wataru being a romance option in the game.
They Wasted a Perfectly Good Character: Is your favorite character not one of the Triplets, or Subaru? Too Bad! If not they will get little time with Ema. The novels push others to the background in order to develop four characters. There are 13 siblings. Thankfully each character has a route in the game where they are developed.
They Wasted a Perfectly Good Plot: The end of Season 1 teased that Hikaru, Louis, Ukyo and some of the other lesser seen characters would get more relationship development with Ema. But come season 2, nope. It ended after one volume and focussed on the Natsume, Ema, Subaru love triangle. Then Ema simply gets together with Subaru and apparently has a kid. That's it. Fans hope that if there is a season three of the anime, that it will focus more on these characters.