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