Full list of all 38 Danganronpa: Trigger Happy Havoc achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Finished every chapter
Finished Chapter 5
Cleared the 20 SP threshold
Finished Chapter 4
Destroyed 100 white noise lines across all class trials
Enjoyed the exciting excitement of the MonoMono Machine 100 times
Finished Chapter 3
Collected 50 unique presents
Finished Chapter 2
Cleared every class trial without having to retry a single time
Finished Chapter 1
Cleared every class trial without using your Concentration skill a single time
Cleared the 10 SP threshold
Finished the Prologue
Filled in every page of Kiyotaka's Report Card
Filled in every page of Byakuya's Report Card
Filled in every page of Mondo's Report Card
Filled in every page of Leon's Report Card
Filled in every page of Hifumi's Report Card
Filled in every page of Yasuhiro's Report Card
Filled in every page of Sayaka's Report Card
Filled in every page of Kyoko's Report Card
Filled in every page of Aoi's Report Card
Filled in every page of Toko's Report Card
Filled in every page of Sakura's Report Card
Filled in every page of Celeste's Report Card
Filled in every page of Junko's Report Card
Filled in every page of Chihiro's Report Card
Filled in every page of every character's Report Card
Collected 999 Monocoins
Collected every possible present
Cleared School Mode once
Saw every possible School Mode ending
Cleared the 30 SP threshold
Unlocked all gallery items
Cleared a class trial without taking any damage
Destroyed 500 white noise lines across all class trials
Earned every other achievement in the game