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