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