In the Realm of Ash & Sorrow by Kenneth W. Harmon

When the spirit of an American airman befriends a Japanese woman and her daughter in the days before the Hiroshima bomb, he races against time to save the ones he loves the most.
When American WWII bombardier Micah Lund dies on a mission over Japan, his spirit remains trapped as a yurei ghost. Dazed, he follows Kiyomi Oshiro, a war widow struggling to care for her young daughter, Ai, as food is scarce, work at the factory is brutal, and her in-laws treat her like a servant. Watching Kiyomi and Ai together, Micah’s intolerance for the enemy is challenged. As his concern for the mother and daughter grows, so does his guilt for his part in their suffering.
Micah discovers a new reality when Kiyomi and Ai dream—one which allows him to interact with them. While his feelings for them deepen, imminent destruction looms. Hiroshima is about to be bombed, and Micah must warn Kiyomi and her daughter.In a place where dreams are real, Micah races against time to save Kiyomi and Ai, while battling the old beliefs he embodied as a soldier and his idea of family.In the Realm of Ash and Sorrow is a tale about love in its most extraordinary forms—forgiveness, sacrifice, and perseverance against impossible odds.