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