DANGANRONPA 2 AND V3 SPOILERS
Ibuki's death made me really sad. She was my favorite character in DR2 and the moment that video played in the Hospital I knew something bad happened to her. Granted the person in the video wasn't her, but still. Ibuki was also sick during this chapter and the killer took advantage of that. Mikan became my least favorite character in DR2 because of this chapter. I didn't like Mikan at first and found her annoying, but after finding out she killed Ibuki and Hiyoko she immediately became my least favorite character.
Other than Ibuki's death, Gundham's and Chiaki's executions were also really sad. Gundham's execution never fails to make me tear up and as for Chiaki.... well I was really attached to her and found her extremely relatable and I honestly didn't think she would get executed. Doesn't help that Gundham was my second favorite character and Chiaki my third.
In V3, Gonta's entire trial was really sad. He didn't even know that he killed someone. Such a good and gentle character didn't deserve such a brutal execution... Kaede's execution was also very sad, but not as sad as Gonta's.