A fisherman found the still legible piece of paper sitting on a sticky flatfish in his catch on Thursday, along with a torn-off string and the fragment of a red balloon. He opened the folded paper, discovering it was a handwritten letter from a six-year-old girl at an elementary school in Kawasaki, 150 kilometres (93 miles) away from where the fish was caught off Choshi port. The sender, Natsumi Shirahige, and her friends released letters as part of events to mark the school's 120th anniversary, which was in 1993."Our school is 120 years old... If you pick up this letter, please write to me," the letter reads, listing the school's address. The 52-year-old fisherman said the letter was a nice surprise. "I've been in fishing for a long time but this is unbelievable," the smiling man told the Asahi television network. Shirahige, now a 21-year-old university student, said: "I can't get over the wonder of how the letter survived 15 years. I never expected I'd get a reply this way."