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