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