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!
Turn down sex, but keep your true love.
Witness Simon's Transformation with Diana and someone special...
Get Shot in the head by Malix.
Start your Adventure with Diana.
Obtain True Power.
Get Proposed to by Andrew.
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.
Go To Paris with Naomi.
Prove Your Love to Suzu.
Obtain True Freedom.
Be Baptized by Angels.
Be Eaten Alive by Diana's Pit Beast.
Unlock the Second Set of Bloopers!
Fight Malix Yourself.
Find Harold Anderson's Magic Books.
Unlock the First Set of Bloopers!
Dodge Malix in time.
Impress the House Party Guests.
Prologue Completed!
Rename the Main Character.