All spoilers will be unmarked ahead. You Have Been Warned!

open/close all folders

Main installments:

Danganronpa: Trigger Happy Havoc

In IF, Monokuma attempts to turn the group against Sayaka by telling them how she planned to murder Leon and frame Makoto for it, but before he can, he's destroyed by Leon, who thought he was trying to take her hostage. Sayaka later plans to confess to Leon about what she was originally planning to do. Leon thinks it's a completely different kind of confession...
Sakura had two goals in mind when she committed suicide: she wanted to stop her friends from killing each other and to start the chain of events that would bring about the mastermind's downfall. She succeeds on both accounts.
The fact that Sakura achieved her goals, and that her death was a suicide means that Hiro's prediction that there wouldn't be any more murders was actually correct.

Danganronpa 3: The End of Hope's Peak High School

Danganronpa 2: Goodbye Despair ended with the survivors of the Killing School Trip shutting down the simulation with the confidence that they could preserve their memories of themselves and each other without falling back into Despair, and staying behind on the island in the hopes that their comatose classmates would wake up someday, despite the fact all of these were entirely impossible because of the design of the simulation. Come Side:Hope, and we see that they succeeded.
Natsumi's title of Ultimate Little Sister was never acknowledged by Hope's Peak and she was thrown in the Reserve Department. This makes Fuyuhiko's statement in the second game, where he refers to his sister by this title and sees this as her talent, very heartwarming.
Kizakura's sudden attachment to Kirigiri's group seemed to be just a case of The Gadfly, only for Side:Despair to reveal he promised Jin that he would keep an eye on his daughter for him.
Kyoko takes off her glove to console Makoto in episode 9. This is even more intense considering that in the first game, she mentions how much she dislikes taking off her gloves, and probably would do it only for someone she considers family.
While still horribly tragic, Kimura's death takes on a silver lining in Side:Hope, as it's revealed that she was able to posthumously save Kyoko.