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