Chiaki Nanami's Punishment

Chiaki Nanami's Punishment (七海 千秋のおしおき Nanami Chiaki no oshioki) is an execution featured in Danganronpa 3: The End of Hope's Peak Academy - Side: Despair, with Chiaki Nanami being executed.

Sequence
Chiaki is forced into a dungeon maze full of dangerous traps. Forced to escape to reunite with her friends, she kept moving through the halls but had activated a hidden switch on the floor, allowing a spike to impale her foot. Not giving up on hope, Chiaki is then fired with metal balls that injures her right eye and arm. As Junko Enoshima, who watches her through cameras in the dungeon, starts a countdown. Chiaki desperately tries to limp to safety only to be speared in the knee. Junko proceeds to mockingly state that she has a despairingly bad temper. At the end of the maze is a large door marked "GOAL", behind which stood Chisa Yukizome and her classmates. Upon Chiaki opening the door, she saw her classmates and teacher happily waiting for her. Chisa reaches out for Chiaki but she only happens to be an illusion; instead a spear fired and went through Chiaki's body. Simultaneously a bed of spikes appear around her, catching her as she fell.

Unlike other executions, it does not end in her immediate death, allowing Izuru Kamukura to talk to her briefly. It is also more eventful and tortures her a bit more before she dies.

Aftermath
The rest of Chiaki's classmates who were forced to watch the brainwashing recording of Chiaki's execution eventually fall into despair and become part of Ultimate Despair who will begin The Tragedy.

Trivia

 * Unlike other formal executions, only its broadcast is "hosted" by a Monokuma as a stuffed bear; Junko herself directed the execution through video screens.
 * This is by far the longest execution in the series, taking up over half the episode in which it takes place. Comparatively, most other executions last around 2 minutes maximum.
 * Chronologically, this is the first formal execution in the Danganronpa series.
 * Interestingly, the execution of Chiaki's AI counterpart happens to be the last formal execution in the Hope's Peak Academy Arc.
 * Chiaki's death in Side: Despair is very similar to Mukuro's death in Danganronpa: Trigger Happy Havoc: being suddenly impaled by dozens of spears. The deaths also double as acts of betrayal from those who were closest to them (Junko, in Mukuro's case, and Chisa, in Chiaki's case).
 * Interestingly, the death of Chiaki's AI counterpart parallels Junko's death, with the two going through a long sequence of painful events before ultimately getting crushed.
 * Considering these facts, it's also worth nothing that Mukuro was the first person to be executed during the Killing School Life, while Junko was the last.
 * It should also be noted that her AI counterpart in the stage play is executed by spear impalement as well.