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