Here is the full list of all 12 Heirs And Graces achievements.
Unlock Eloy Romance Scene
Pass all the main plot skill checks
Reach 90 Reputation before the end
Unlock Eloy sexy Scene
Trigger a jealousy scene
Unlock Borges Romance Scene
Unlock Kamal Romance Scene
Unlock Vincent Romance Scene
Unlock Borges sexy Scene
Unlock Kamal sexy Scene
Unlock Vincent sexy Scene
Unlock the bad ending scene