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