Here is the full list of all 46 Ys Origin achievements.
Unlock Yunica's schoolgirl outfit.
Unlock all other achievements.
Fight all enemies (excluding bosses) enough times to fill in all blank data entries for them in your monster journal.
Complete four or more consecutive stages in Arena Mode without taking any damage.
Enable "No-Fall" mode for the first time.
Complete Boss Rush on Nightmare difficulty with all versions of all characters.
Obtain all blessings/upgrades with all characters.
Complete any Arena stage with less than 10 HP.
Complete Boss Rush on Hard difficulty with any character.
Complete Boss Rush on Normal difficulty with any character.
Complete Boss Rush on Easy difficulty with any character.
Unlock every character's EX version.
Purchase everything available in the Bonus Shop.
Fight and defeat Pikkardon in Arena Mode.
Unlock any character's EX version.
Spend more than 2,000,000 SP in the Bonus Shop.
Unlock Adol the Red in the Bonus Shop.
Complete the game as Yunica.
Complete the game on Nightmare difficulty with all characters.
Defeat the Demonic Core end boss with all playable characters.
Thwart the Darkling lackeys in the Demonic Core as both Yunica and Hugo.
Defeat the mid-boss in the Hall of Reflection with all playable characters.
Give Roda Fruit to all of the Roos in the tower with every character.
Defeat the Blighted Blood end boss with all playable characters.
Defeat the Silent Sands end boss with all playable characters.
Defeat the mid-boss in Rado's Annex as both Yunica and Hugo.
Defeat the Guilty Fire end boss with all playable characters.
As Yunica, persevere against an unbeatable foe in the Guilty Fire.
Defeat the final boss and obtain the game's true ending.
When playing as neither Yunica nor Hugo, completely refrain from using Burst until the final encounter.
As Hugo, defeat Toal; as Toal, defeat Hugo.
Defeat the Flooded Prison end boss with all playable characters.
Defeat the Wailing Blue end boss with all playable characters.
Complete Boss Rush on Nightmare difficulty with any character.
Complete the game as Hugo.
Unlock Toal by completing the game as Yunica or Hugo.
Complete the game on Very Easy difficulty with any character.
Complete the game on Easy difficulty with any character.
Complete the game on Normal difficulty with any character.
Complete the game on Hard difficulty with any character.
Complete the game on Nightmare difficulty with any character.
Obtain all blessings/upgrades with any character.
As Hugo, obtain ultimate power... then let it go to waste completely.
As Hugo, emerge victorious during your emotional encounter in the Guilty Fire.
Thwart Epona's early-game challenges as both Yunica and Hugo.
Purchase your first blessing/upgrade.