Here is the full list of all 46 Conception PLUS: Maidens of the Twelve Stars achievements.
Complete Harem ending.
Complete Reone's ending.
Complete Mirei's ending.
Complete Lillith's ending.
Complete Arie's ending.
Complete Tarua's ending.
Complete Sue's ending.
Complete Farun's ending.
Complete Collette's ending.
Complete Femiruna's ending.
Complete Ruka's ending.
Complete Alfie's ending.
Complete Yuzuha's ending.
Complete Normal ending.
Complete main scenario.
Complete Mahiru's ending.
Have 100 Star Children go independent.
Clear 4 Constellation Labyrinths.
Clear 3 Constellation Labyrinths.
Give birth to the special class "Sage."
Perform the Tri-Mating ritual.
Clear 2 Constellation Labyrinths.
Have 25 Star Children go independent.
Clear 1 Constellation Labyrinth.
Insta-kill 100 Impurities.
Visited the Map Point "Gift Shop."
Visited the Map Point "Scavenger."
Give birth to 12 Star Children.
Visited the Map Point "Day Camp."
Give birth to your first Star Child.
Obtain all achievements.
Clear 6 Constellation Labyrinths.
Clear 12 Constellation Labyrinths.
Complete a total of 8 Chain Combos.
Complete a total of 100 Chain Combos.
MECUNITE a total of 10 times.
Use all Team Colors.
Give birth to the special class "Ninja."
Give birth to the special class "Dungeon Master."
Give birth to the special class "Bondsman."
Give birth to a Star Child of each class.
Give birth to 200 Star Children.
Complete all quests.
Obtain all weapons.
Obtain all armor.
Obtain all accessories.