Ibuse was known and appreciated for most of his career, although it wasn't until after the war that he became famous. He won the inaugural Yomiuri Prize in 1949 for "". In 1966 he published his novel "Black Rain", which won him international acclaim and several awards, including the Noma Prize and the Order of Cultural Merit, the highest honor that can be bestowed upon a Japanese author. The novel draws its material from the bombing of Hiroshima and the title refers to the nuclear fallout. Ibuse was not present at the time of the bombing, but used the diaries of survivors to construct his narrative. An earlier story by Ibuse, "Kakitsubata" ("The Crazy Iris", first published in 1951), deals with similar themes.