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