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!
Get Shot in the head by Malix.
Be Eaten Alive by Diana's Pit Beast.
Obtain True Power.
Witness Simon's Transformation with Diana and someone special...
Start your Adventure with Diana.
Be Baptized by Angels.
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.
Turn down sex, but keep your true love.
Rename the Main Character.
Go To Paris with Naomi.
Prove Your Love to Suzu.
Obtain True Freedom.
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.
Prologue Completed!