Here is the full list of all 25 Seduce Me the Otome achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Preview the start of Seduce Me 2: The Demon War!
Witness Simon's Transformation with Diana and someone special...
Rename the Main Character.
Obtain True Freedom.
Get Shot in the head by Malix.
Start your Adventure with Diana.
Be Baptized by Angels.
Obtain True Power.
Be Eaten Alive by Diana's Pit Beast.
Give Damien his Humanity.
Kiss Erik under the Moonlight.
Accept Sam for the Man he is.
Share some Cake with Matthew.
Go To Paris with Naomi.
Prove Your Love to Suzu.
Get Proposed to by Andrew.
Fight Malix Yourself.
Get Proposed to by James.
Turn down sex, but keep your true love.
Unlock the Second Set of Bloopers!
Find Harold Anderson's Magic Books.
Unlock the First Set of Bloopers!
Dodge Malix in time.
Impress the House Party Guests.
Prologue Completed!