Here is the full list of all 24 Learn Japanese To Survive! Katakana War achievements.
Complete lesson 6.
Complete lesson 7.
Complete lesson 8.
Complete lesson 9.
Complete lesson 10.
Clear the game.
Complete 10 side quests.
Complete 15 side quests.
Complete all 20 side quests.
Maximize all character's affection levels.
Obtain the ultimate sword.
Complete lesson 5.
Maximize a character's affection level.
Complete 5 side quests.
Visit the Challenge Castle.
Complete lesson 4.
Unlock the power of the Crystarium
Try 3 different types of seafood.
Unlock the potential of corn soup.
Complete lesson 3.
Complete lesson 1.
Complete lesson 2.
Complete a side quest.
View a character's affection event.