Here is the full list of all 31 Fatal Twelve achievements.
Start the game 12 times
Select every choice at least once.
View a story about a certain encounter
Reply to the confession
Get ending 2
Get all endings
Get all CGs
Get ending 3
Get bad ending 4
Open Scene Replay Mode
Open Gallery Mode
Get ending 1
Twelfth week's election concludes
Eleventh week's election concludes
Tenth week's election concludes
Get bad ending 3
Get bad ending 2
Ninth week's election concludes
Eighth week's election concludes
Switch languages
Get bad ending 1
Seventh week's election concludes
Sixth week's election concludes
Fifth week's election concludes
Fourth week's election concludes
Open Summary Mode
Third week's election concludes
Second week's election concludes
First week's election concludes
Open Card Book Mode
Start the game