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