Here is the full list of all 16 London Detective Mysteria achievements.
Obtained all achievements.
Completed the prologue.
Used the Detective Diary for the first time.
Discovered true love with Holmes.
Discovered true love with Watson.
Discovered true love with Lupin.
Discovered true love with Jack.
Discovered true love with Akechi.
Witnessed a performance you'll never forget.
Discovered true friendship with Marple.
Discovered true friendship with Kobayashi.
Gathered everyone for a lovely picnic.
Persevered to the very end.
Completed all epilogues.
Discovered half of the event artwork in the game.
Discovered all event artwork in the game.