Here is the full list of all 13 My Secret Pets achievements.
Completed with All Endings.
Completed All Main Scenarios, Sequels, and Date Scenarios.
Completed with "Reito" Happy Ending.
Completed with "Reito" Miracle Ending.
Completed with "Ramin" Happy Ending.
Completed with "Ramin" Miracle Ending.
Completed with "Lufna" Happy Ending.
Completed with "Lufna" Miracle Ending.
Completed with "Lize" Happy Ending.
Completed with "Lize" Miracle Ending.
Completed with "Assam" Happy Ending.
Completed with "Assam" Miracle Ending.
Completed the Prologue.