(I didn't wanna leave this account with no new posts anymore, so I did this. I promise I will write about other characters in later posts, but again, I can't help it, Satsuhiko is my favorite ship after all.)
Before Chapter 4, they had quite some moments together. These display their wholesome friendship and allow us to see how they become closer and closer as time goes by. I also love this moments because it shows that it does not matter if they are alone or with others, they just seem to love each other company so much to the point of being together most of the time. If I remember correctly, all of them are:
Before the moment when Haruhiko broke the nameplates, they were having fun along with Kiyoka as well to forget the serious situation they're in.
That moment where they came late to the breakfast gathering because they were playing basketball before.
When they were playing poker, which later Maeda joined in the game.
When they were both watching Maeda's luck in the casino slot machine, along with Teruya and Kinji.
The reason why I wanted talk about this is due to all of this is sometimes overlooked, and it what makes their love in Chpater 4 not seem random. Imagine if Haru and Satsuki never had a single interaction during the killing game and then, all of a sudden, Haru finds that famous picture of him and Satsuki kissing. Then the case and class trial proceeds to be the exact same as we all know. That would make the case extremely random, rushed and weird, that's the importance behind those moments.
With that out of the way, I'm gonna talk about Chapter 4. It is the chapter that is mostly dedicated to make Satsuhiko / Kobaira shine. And I really love how before Haru finding the pic I mentioned in the paragraph above, you can already see how their friendship is slowly turning into love.
And now, the moment where I definitely felt upset. The sacrifice. Even if it made cry, perfection is how I would this bit played out. Their new love beginning but ending tragically soon by Haruhiko's death, and also how in here, knowing that Haru didn't even think it twice when sacrificing himself, it shows how of a great person he is and how great of a character he has become. And for Satsuki, the sacrifice made her stronger, made her become a better character than she already was. I also believe that one of the reasons why she just wanted to die (apart from being a really sweet soul who is honest and wants the best for the others.) was because she couldn't stand living without Haru and although is extremely sad, it just shows how much they loved each other.
And of course, I love how were a couple before the killing game and then were able to fall in love again.
Other things about Satsuhiko: (These are not opinions)
Haru becomes much less agressive towards Satsuki's silly remarks over time.
You can see how in Chapter 4, Haruhiko favors and protects Satsuki already before the sacrifice. This can be seen when he offers Satsuki to steal food and when they were caught for stealing said food, where Haruhiko went to protect Satsuki and lie to protect her.
During Chapter 4, Satsuki only trusts Haruhiko. She only hangs out with him and nobody else.