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