Beginning at episode one, they already showed us the relationship of the main characters, and the writing there was so superb. So, it became easy to understand what to expect from the show.
And on that episode, the best part was when Rikuo confessed his love, the emotions in the face, especially in the eyes were accurate enough to understand what the two of them were feeling at that scene.
(Rikuo being rejected by Shinako...)
I also like the fact that each episode has a meaningful dialogue, an example was from episode 10:
"Growing up means you end up with things you need to protect. That's just how it is."
And from the finale:
"We overthink things and look back at yesterday... But still, our silly lives go on."
In episode 5, when Haru rejected Kouichi Minato's feelings for her, I really loved what she did after. She sincerely asked for the guy to shake hands with her, And I just thought, that's a very mature way to have a proper ending between them.
Episode 9 for me had the most romantic, exciting ending scene. And the new ending credits after that really helped elevate the mood, like it was a sign of something new.
However, the appearance of Rou in episode 11 felt like something that wasn't thought about thoroughly. I mean, they wanted a shocking cliffhanger sure, but for me, it just felt lackluster. He just entered the scene without any build-up, and it just didn't have much dramatic effect.