The case that started it all!
Makoto peeks over your shoulder and starts screaming. Don't worry about him. Let's talk about this case.
Sayaka's death in Trigger Happy Havoc has the difficult task of drawing players in and setting expectations for the entire series. Unfortunately, it does have a serious flaw: the 11037 clue makes things a bit too easy, meaning the player is able to pinpoint the killer pretty much the moment they discover the body. I also think Kyoko holds Makoto's hand a little too heavily, rather than letting the player work things out for themselves.
That said, I still think Sayaka's murder is a pretty strong starting case overall! In particular, the central twist - that Sayaka was the one planning murder in the first place - is a great one. It's not necessarily a surprising development for the player, who may well have noticed that Sayaka's behaviour is a bit fishy, but it adds an interesting emotional layer to a case that would be much too straightforward otherwise. Poor Makoto, slowly realising that the victim he cared so much about was planning to commit murder and frame him for it.
The way Danganronpa puts so much focus on Sayaka and then kills her immediately, in such a bloody and shocking way, is also a good way to drive home the anyone-can-die concept of the game. It tells us straight away that, if a character seems to be significant, that's no guarantee of their safety. We're now primed to view any character in the school as a potential victim or murderer, which is exactly what the characters trapped in this game have to struggle with.
I really like that Kyoko tells Makoto he can move past this after the first trial, and Makoto refuses. He's going to survive these deaths, but he's not going to move past them; they're a part of him now. It's a nice moment for his character, I think.