In this article I intend to discuss the prewar life and literary activity of one of the most famous writers of atomic-bomb literature, Hara Tamiki. Unlike such famous writers as Oe Kenzaburo and Ibuse Masuji, who wrote about the atomic tragedy in Hiroshima, despite not having experienced it, Tamiki became famous worldwide due to one short novel, Summer Flowers, which was published by 1946, and which was based on his own experience. The novel was a complete account of a reality that surpassed anybody's imagination. However, Tamiki actually wrote some similar fictional stories before the Second World War, being in some way a prophet of the coming war. His characters are often put in extreme situations, facing death or incurable sickness, searching for the real meaning of life and death. The anxiety of human existence was the main theme of his prewar writings. Also, we can deduce from his works how influential his beloved older sister, Tsuru, was. She was a Christian. Tamiki himself never became a Christian believer, but her existence is perceptible in his works. I shall analyse a few of his writings in which we can find all the elements mentioned above. These include Flames (Hono), Christ (Kirisuto), and Prairie (Koya).