Here is the full list of all 25 Conor Origins - there are T Trilogy achievements.
Accept Dave for who he is and go with him
Spend time with Dave but miss chance to confess
Support Dave's interests
Enjoy manga with Dave
Get the ending where Dave disappears.
Have Dave save your life
Try to stop worrying about Dave
Let Jolie have Dave
Get arrested for attempted murder
Confess your feelings to Dave
Spend your life trying to find Dave's killer
Swear to be there for Dave when he's in trouble
Get together with Dave after escaping death
Got away from Dave
Hear Dave's confession
Burn to death
Get the true ending in Trapped
Get abandoned by Mila
Request to stay with Mila
Leave Mila behind
Agree to split up with Mila
Escape your cell
Found the wrong key
Give up on escaping prison
Finished reading through They Cannot Hear Me