DRAGON QUEST XI: Echoes of an Elusive Age

During Act 3 (Post Game) if you follow the story you will eventually unlock a set of trials in the underground ruins of Zwaardsrust. These trials will have you traverse maps of places you have previously visited until you reach a chamber with a boss that you must defeat in a set amount of turns. If you succeed you will be offered a selection of five wishes. One of the wishes available is "I wish Gemma and I were married!". After selecting this, return to Cobblestone and talk to Gemma at your house to rest the night and upon waking up this trophy will unlock.