Twenty-one-year-old fresh graduate Aran had always believed her relationship with Lene was more than just a sibling-like bond, until she received the cruelest rejection she could ever have imagined. She can only embrace her pain and fly abroad to continue her studies, hoping that one day she will be able to forget Lene. Then one day, a mysterious package arrives along with a handwritten letter. There is no name, but Aran recognizes the handwriting instantly. She decides to fly back to Thailand, determined to finally close this unresolved chapter. The moment she arrives, however, she is met with devastating news. Just as she's about to say her final goodbye, she overhears a conversation suggesting that Lene's death may have been caused by someone close to her. When she wakes up five years in the past, to the moments after her rejection, red thread from the funeral still in hand, she tells herself this time will be different. This time, she will be the one to protect Lene.