I progressed the game to autumn and waited until night came.
I found a huge tree and sat at its base for a bit until the sky turned red. When I turned around there was a weird floating fox head that popped out from behind a tree. I ran toward it and it disappeared.
I approached the towers that teleport you and the sky got swallowed up in shadow.
During that same night I went to the circle of animal statues and sat down for a bit until the sky turned red once again and the stars began to pulse. Once this happened I looked around and saw the silhouette of a man. I chased him for a little while until he disappeared. The trophy then unlocked.
I'm not entirely certain of the trophy requirements, but that is how I got it. My guess is that there are a number of special events that can happen (only in autumn?) and you are required to see some or all of them.
*** Spoiler - click to reveal ***After unlocking this trophy I went over to the house in the middle of the night. Approaching it causes the sky to turn purple. Music that sounds like JRPG town music begins to play.