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...
Give Damien his Humanity.
Start your Adventure with Diana.
Get Proposed to by Andrew.
Go To Paris with Naomi.
Obtain True Power.
Prove Your Love to Suzu.
Be Baptized by Angels.
Be Eaten Alive by Diana's Pit Beast.
Fight Malix Yourself.
Get Shot in the head by Malix.
Share some Cake with Matthew.
Accept Sam for the Man he is.
Kiss Erik under the Moonlight.
Dodge Malix in time.
Get Proposed to by James.
Turn down sex, but keep your true love.
Obtain True Freedom.
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.