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