Here is the full list of all 34 Pawn achievements.
Do your job, more or less...
Nail the Free Time Investigation events
Pick the wrong weakness
Botch the investigation
Get the good ending
Interrogate Kojima
Interrogate Umehara
Interrogate Aonuma
Interrogate Higuchi
Cleared the fifth chapter
Join your fellow teachers and paint the town red
Taste Noriko's sushis
Follow the chief to a wet place...
Be a man
Get any bad ending
Kick back on your couch, all by yourself
Interrogate Tanabe
Interrogate Taguchi
Interrogate Okawa
Cleared the fourth chapter
Interrogate Higashiyama
Interrogate Ichiyusai
Interrogate Hiroyuki
Cleared the third chapter
Interrogate Hamacho
Interrogate Satoya
Interrogate Shimada
Cleared the second chapter
Cleared the first chapter
Cleared the prologue