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