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