Shusaku Endo (遠藤周作), born in Tokyo in 1923, was raised by his mother and an aunt in Kobe where he converted to Roman Catholicism at the age of eleven. At Tokyo's Keio University he majored in French literature, graduating BA in 1949, before furthering his studies in French Catholic literature at the University of Lyon in France between 1950 and 1953. A major theme running through his books, which have been translated into many languages, including English, French, Russian and Swedish, is the failure of Japanese soil to nurture the growth of Christianity. Before his death in 1996, Endo was the recipient of a number of outstanding Japanese literary awards: the Akutagawa Prize, Mainichi Cultural Prize, Shincho Prize, and Tanizaki Prize. (from the backcover of Volcano).
This was written as a sequel of 海と毒薬(The Sea and Poison). As long as I know, there is no translation into English despite 海と毒薬 have. Main Character of 海と毒薬 Suguro 勝呂 is also one of main characters. In 海と毒薬 author compared Japanese moral with Western one and critisized weakness of Japanese conscience. After long time from war, he might have a daubt "Is there absolute virtue ?". In the Bible there is a word "Vengence Is Mine.". But Mr. Endo's God never judge only weeps for his Sin. He argued the Japanese have been able only to interplet the concept of Unique God like this.