In "Summer Time Rendering," mysterious occurrences on the island include strange time loops where characters are trapped in repeating cycles of events. These time loops play a significant role in the anime as they create a sense of mystery and suspense, forcing the characters to confront their past actions and make decisions that will ultimately determine their fate. The concept of time loops adds a unique element to the story, keeping viewers engaged as they try to unravel the mysteries surrounding the island and its inhabitants.
