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