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