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