The shadows on Hitogashima Island have a profound impact on the events that unfold, as they are depicted as possessing mystical powers that can influence the actions and decisions of the island's inhabitants. These shadows are believed to hold secrets, tempt individuals into making questionable choices, and even have the ability to manipulate the minds of those who encounter them. As a result, the shadows create an eerie and unpredictable atmosphere on the island, shaping the narrative and adding tension to the characters' journey.