Letters Yoon Byungryeol (尹秉烈) exchanged the letters with his family when he was mobilized to the Kamui cCoal Mmine, at the Sorachi mining station of Hokkaido Colliery & Steamship Co., Ltd., located in Hokkaido, Japan. It’s 10 thatis the number of them letters that remainshas been left. Every letter that was sent q-from the mines werewas strictly censored strictly by the Japanese manager q-andso that the laborers q-and families could only write only greetings.